Practical skills

Raw and synthetic materials

Plants

Adaptations

Light & dark

Magnetism

States of matter

Rock cycle

Human anatomy

Ecosystems

Electrical circuits

Sound

Separating mixtures

Physical and chemical changes

Reproductive cycles

Notable scientists

Forces

Space

Particles in physical and chemical changes

Sustainability

Humans and animals over time

Diet and lifestyle

Light

History of science

Science

Y5 Science

Key Stage 2

Year 5

UNIT

In this lesson, we will learn what makes a substance pure or impure. We will also learn to draw diagrams to represent the particles in pure and impure substances.

What makes something pure?

﻿Hello everybody. My name's Ms. Couves, what's your name? Nice to meet you. I'm so excited to be teaching you today. Today I'm going to be teaching you some science. Science is my absolute favourite subject, and we're going to be learning chemistry, which is my favourite part of science. Before we get started, I thought I would tell you about what I've been doing during the lockdown. During the lockdown, I've been growing plants in my garden, this is one of my chilli plants. Can you see how the chilies are turning from yellow at the top to red at the bottom. When they are all red, they will be ready for me to eat. Can you see this one is almost ready. I'm so excited to taste them. What have you been doing during the lockdown? That sounds exciting too. Today we're going to learn about what makes something pure. It's a really important part of science. And we're going to start by looking at what makes something a solid, a liquid, and a gas, and imagining what the particles that make up those compounds look like. So, if we're ready, let's get started. We're going to start by thinking about solid, liquids, and gases, and what they look like. We're then going to talk about the how the particles behave. And then we're going to talk about what makes something pure or impure. Everything is made up of particles and those particles behave in different ways depending whether something is a solid, a liquid, or a gas. In this lesson, you are going to need three things, an exercise book or paper, a pencil, and a glass of water. If you don't have one of these things, pause the video now and go and get them. First we're going to look about solids, liquids, and gases. We're going to start by looking at water. When we normally think of water, we think of water in a cup, is water in a cup a solid, a liquid, or a gas? Water that we get from the tap and put into our cups, is liquid water, but actually water can come in a solid form, a liquid form and a gas form. When water is a solid, we call it ice. What do we call solid water? Ice. When water is in the gas form we call it steam. What do we call gaseous water? Steam. All three of these substances are made of the same type of particle called the water particle. So all of these substances are all water. Everything is made of particles. Particles are tiny, tiny, tiny, tiny bits of matter that we can't see. And different substances have a different type of particle. The particle in water, ice, and steam is the water particle. So, if the particle is the same, why don't all of these substances look so different? Well, it's because the particles are arranged in different ways. Which particle is used to make ice, water, and steam? The water particle is used to make ice, water, and steam. What's the difference between ice, water, and steam? The arrangements of the particles are different in ice, water, and steam. Let me show you how the particles are arranged in ice, water, and steam. So, I'm going to show you what the particles look like in ice, water, and steam. In ice, the water particles are arranged in ordered rows. I draw my particle as a circle, and I know that my particles in ice are touching and in ordered rows. So I'm going to draw all of the particles, the same size in a nice ordered row. Why do you think I'm making sure that my particles of ice are the same size? My particles are ice, of ice are the same size because they're the same type of particles. So all of my particles should be exactly the same. What were the two important things about my particles in ice? The particles in ice are touching and they're in ordered rows. Actually, it's not just ice that has particles arranged like this, all solids have particles that are arranged so that the particles are touching and in ordered rows. What do the particles in a solid look like? Particles in a solid are touching and arranged in ordered rows. Let's think about water. Water is a liquid. The particles in a liquid are still touching, but they're not in ordered rows, they have a random arrangement. Again, I'm going to tool my particles as circles. They're going to be the same colour and size because they're the same particles as in ice. But this time they're touching, but not in an ordered rows. What's important about the particles in water, liquid water? They are touching, and they have a random arrangement. This is what particles look like in a liquid. What do the particles look like in a liquid? Particles in a liquid are touching, and have a random arrangement. Pause the video and draw yourself the particles in a solid and the particles in a liquid. Press play when you're ready to continue. Finally, we're going to look at the particles in a gas. Steam is a gas. Particles in a gas are not touching. We're still drawing up articles within the same colour and the same size, because they're still the same particle. What particle makes ice, water, and steam? The water particle. So all of these circles represent the water particle. What is the difference between ice, water, and steam? The difference between ice, water, and steam is that the way the particles are arranged. In steam the particles are not touching. And they're also moving very fast. We show that the particles in steam are moving very fast by drawing these lines to represent the movement of particles. What do the particles in gases look like? The particles in gases are not touching and they're moving very fast. Pause the video and make sure you have a diagram to represent solids, a diagram to represent liquids, and a diagram to represent gases. Check your diagrams look like mine. How do we know that the same particle is used to make ice, water, and steam? We know that the same particle is used to make ice, water, and steam because the particles look the same. They have the same colour and the same size. Remember that we are representing the particles in ice, water, and steam using these diagrams, this is not what they actually look like. So, let's think about a new substance, wood. Wood is made from wood particles. What particles is wood made from? Wood particles. Is wood a solid, a liquid, or a gas? Wood is a solid. So we're going to be thinking of drawing the particles in a solid. In a solid, should the particles touch? Should the particles be ordered? And should they be moving fast? Now you've answered those three questions, have a go at drawing the particles in wood. Press play when you're ready to continue. Wood is a solid. The particles in a solid are touching and in ordered rows, but not moving very fast. In fact, particles in a solid, just vibrate on the spot very, very slightly. Tick your answer if you've got it correct and correct it if you need to. Let's think about another material. What do the particles in oil look like? Is oil a solid, a liquid, or a gas? Should the particles be touching? Should the particles be ordered? Should the particles be moving fast? Pause the video and have a go at drawing the particles in oil. The particles in oil are arranged so that they are touching, but in a random arrangement because oil is a liquid. What about the particles in helium? Helium is inside a helium balloon. Is helium a solid, a liquid, or a gas? Should the particles touch? Should the particles be ordered? Should the particles be moving fast? Pause the video and draw the particles in helium. Press play when you're ready to continue. Helium is a gas. The particles in a gas are not touching and moving very fast. Tick your answer if you've got it correct, or fix it if you need to. Now we know how the particles are arranged. We're going to have a think about the how particles behave? Is ice a solid, a liquid, or a gas? Ice is a solid. Solid particles vibrate on the spot, vibrates on the spot. This is a solid particle. They vibrate on the spot. Show me what a solid particle does. Yes, they vibrate on the spot. Liquid particles can slide past each other. Liquid particles can slide past each other. Show me what liquid particles can do. That's right. They can slide past each other. Gas particles move very fast in all directions. Gas particles move very fast in all directions. Show me what gas particles do. Good. They move very fast in all directions. Let's add to our diagram, the movement of particles. How does solid particles move? Solid particles vibrate on the spot. How do liquid particles move? Liquid particles can slide past each other. What about gas particles? How do gas particles move? They move really fast in all directions. Pause the video and make sure you have those notes in your diagram. Press play when you're ready to continue. In which states of matter are particles moving fast in all directions? Point to the screen. Gases are moving fast in all directions. Point to the state of matter in which particles are touching. Particles are touching in solids and liquids. Point to the states of matter where particles are arranged in ordered rows. Particles are arranged in ordered rows in solids. How do the particles in oil behave? Option 1, they are touching and vibrating on the spot. Option 2, they are touching, but can slide past each other. Option 3, they are not touching and move very quickly in all directions, or option 4, they are touching but not moving at all. Option 2, they are touching but they can slide past each other because oil is a liquid. How did the particles in wood behave? Option 1, 2, 3, or 4. Option 1, particles in solid like wood are touching and vibrating on the spot. Show me the particles in solids, that's it, vibrating on the spot. How did the particles in helium behave? Option 1, 2, 3, or 4? Option 1, 2, 3, or 4? Option 3. They are touching, they are not touching and move very quickly in all directions because helium is a gas. Now we're going to think about pure substances and impure substances. What is the difference between pure and impure substances? Helium is a pure substance. That means it contains any one type of particles, the helium particle. How many types of particles are there in a pure substance? There is one type of particle in a pure substance. An impure substance contains more than one type of particle. Air is an impure substance because it contains more than one type of particle. I'm going to show you what this looks like using our particle diagrams. I am going to use different colours to represent the different types of particles. Have a look at the diagram. How does the diagram of air show us that there are two different types of particles? The diagram shows us there's two types of particles, because there are two different coloured particles. How does the diagram of helium show us that helium is pure? The diagram shows us that helium is pure because it contains only one type of particle. Pause the video and write down the definition of a pure substance. You might want to use a diagram to support your answer. What? Pause the video and write down the definition of an impure substance. You might want to use a diagram to support your answer. Let's check those definitions. A pure substance contains only one type of particle. And an impure substance contains more than one type of particle. Pause the video and have a go at drawing a pure solid and an impure solid. Press play when you're ready to continue. In a solid, particles are arranged in ordered rows, but in a pure solid there's only one type of particle, and in an impure solid there's more than one type of particle. Tick or fix your answer. How does my diagram of an impure solid tells me, tell me that there's two different types of particles? My diagram of an impure solid shows me there's two types of particles because there's two different colour circles. Tap water isn't actually pure water. It contains other substances too. We're going to put, going to do a practical to prove this. If you don't have the equipment for this practical, you can just follow along with me. You need to place your cup of water somewhere warm and wait for the water to evaporate. This might take several days. Pause the video and go ask your parent where you can leave your cup of water to evaporate. Press play when you're ready to continue. I started this experiment a week ago and I have my cup here so that we can look at the results. Have a look at my cup. Can you see the marks on the outside? There are some particles from my tap water that are not water particles. Can you see? These are called salt particles. In my tap water there were water particles and salt particles. When the water particles evaporated, the salt particles were left on the outside. If my tap water contains water particles and salt particles, is it pure or impure? My tap water contains water particles and salt particles, so it is impure. Good luck with your experiment. I hope you get to see the salt particles. Remember to complete the quiz, and I'll see you in our next lesson.

In this lesson, we will learn what makes a substance a mixture. We will also learn how to identify mixtures and the benefits of using an alloy over a pure metal.

What makes something a mixture?

﻿Hello, everybody! My name is Miss Couves. It's lovely to see you again. What have you been doing since our last lesson? I have been in my garden, growing lots of lovely plants. Today we're going to learn some more about chemistry, which is great because chemistry is my favourite science. I am so excited for our lesson today, as we're going to do an experiment at the end. That's why I've got my lab coat ready. Shall we get started? We're going to start our lesson today by recapping the knowledge from our last lesson. Then we're going to learn about mixtures and alloys. And then finally, we're going to do an experiment with oil and water. You will need an exercise book and some paper and a pencil. And if you would like to have a go at our experiment, you'll need a glass of water, some oil, and some soap. You'll also need an adult to help you. If you don't have these things, you can do the experiment with me instead. If you need to go and get one of these items, pause the video now, and resume when you're ready to continue. Let's get ready to recap our knowledge. Remember to think really hard. Firstly, we learnt about the three states of matter and how particles were rearranged, were arranged. Which state of matter had particles arranged in ordered rows? A solid has particles arranged in ordered rows. Can you point to the diagram of a solid? Which state of matter has particles arranged randomly but still touching? A liquid has particles arranged randomly but still touching. Can you point to the diagram of a liquid? And which state of matter has particles that are touching and moving very fast? A gas. Gases have particles that are not touching and moving very fast. Can you point to the diagram of a gas? Check your answers. Did you get them right? One of these diagrams shows a pure substance. Which one? How did you know? The diagram on the left shows a pure substance because it only has one type of particle. The other shows an impure substance. How do you know the diagram on the right is an impure substance? The diagram on the right is an impure substance because it contains more than one type of particle. Today we're going to be learning about impure substances. Impure substances are also called mixtures because they contain a mixture of particles. Here are three examples of mixtures, salty water, air, and steel. Salty water contains a mixture of salt particles and water particles. Which two particles are in salty water? Salty water contains salt particles and water particles. Air contains a mixture of oxygen and nitrogen particles. Which two particles are in air? Air contains a mixture of oxygen particles and nitrogen particles. Steel is a mixture of iron and carbon particles. Which two particles are in steel? Steel contains a mixture of iron particles and carbon particles. How do we know that all of these substances are mixtures? All of these substances are mixtures because they contain more than one type of particle. How would we represent this on a particle diagram? We would use two different colours. I'm going to show you the particle diagrams for salty water, air, and steel. I want you to look at how the particles are arranged and how many different types of particles there are. How do we know that these are examples of mixtures? We know they're mixtures because they contain more than one type of particle. When drawing these diagrams, we need to know whether the mixture is a solid, a liquid, or a gas and whether it is a pure substance of a mixture. Let's have a think about some more examples. Squash contain sugar particles and water particles. What state of matter is squash in? How are the particles arranged? How many different types of particles are there? Pause the video, and draw squash as a particle diagram. Press play when you're ready to continue. The particle diagram for squash looks like this. Squash is in the liquid state of matter. So the particles are touching but arrange in a random order. There are two different types of particles, squash particles and water particles. Point to a water particle. Point to a squash particle. Pause the video to tick and fix your diagram. Let's test our knowledge. We're going to answer these five questions. I'm going to read you all the questions and then give you time to pause the video to complete them. Question one, draw a diagram to represent a pure solid. Question two, draw a diagram to represent a mixture of gases. Question three, give an example of a solid mixture. Question four, give an example of a liquid mixture. Question five, give an example of a gaseous mixture. That means a mixture of gases. Pause the video to complete the questions. Press play when you're ready to continue. For our pure solid, we should have our particles arranged in ordered rows and touching. There should only be one type of particle. In question two, a mixture of gases, our particles should be moving fast and not touching each other. It's a mixture, so there is more than one type of particle. So some of your particles should be shaded in. An example of a solid mixture is steel. An example of a liquid mixture is salty water. An example of a gaseous mixture is air. Pause the video to tick and fix your answers. An alloy is a special type of mixture that includes a metal. Metals are usually solids. How are the particles arranged in a solid? Particles in a solid are arranged in ordered rows, and they're always touching. How do the particles behave in a solid? They are vibrating on the spot. Show me a solid. Great. The particles in a solid vibrate on the spot. Bronze is an alloy of two metals, tin and copper. Look at the diagram. How do you know that tin is a pure metal? We know that tin is a pure metal because it contains only one type of particle. Look at the diagram. How do you know that bronze is an alloy? We know that bronze is an alloy because it is a mixture of metals. Bronze contains tin particles and copper particles. Tin and copper are both soft metals, but bronze is very strong. In fact, bronze was used by humans in the Bronze Age to make tools. When you mix metals together to form an alloy, they become stronger. What happens to metals when you mix them together to make an alloy? The alloy is stronger. Steel is another type of alloy. It is a mixture of iron and carbon. Steel is really strong, and it's used as building materials. Why are alloys more useful than pure metals? Alloys are more useful than pure metals because they are stronger. How do we know that an alloy is a mixture? We know that an alloy is a mixture because it contains more than one type of particle. How does the diagram show us that it contains more than one type of particle? The diagram shows this because some of the particles are shaded in and some aren't, to represent different types of particle. What is the benefit of an alloy over a pure metal? Alloys are stronger than pure metals. White gold contains gold particles and platinum particles. What state of matter is white gold in? How are the particles arranged? How many different types of particles are there? Pause the video, and draw a particle diagram for white gold. Press play when you're ready to continue. What do the particles in white gold look like? White gold is a solid, so the particles are touching and arranged in ordered rows. How are the particles, how many different types of particles are there? There are two types of particles, gold particles and platinum particles. Point to a gold particle. Point to a platinum particle. Pause the video to tick and fix your answers. Press play when you're ready to continue. Let's test our knowledge by answering these four questions. I'm going to read you the questions. Then you can pause the video to give you time to answer them. Question one, what is the difference between a pure metal and an alloy? Question two, which metals make the alloy bronze? Question three, how is bronze different from pure metals? Question four, how do you know that bronze is a mixture? Question one, a pure metal contains only one type of particle, whereas an alloy is a mixture of different types of particles. The metals that make the alloy bronze are tin and copper. Question three, bronze is stronger than pure metals tin and copper. Question four, bronze is a mixture because it contains two different types of particle. Pause the video to tick and fix your answers. Press play when you're ready to continue. We're going to investigate mixing with two different substances, oil and water. If you would like to have a go at the experiment, you will need some oil, some water, some washing-up liquid, and a spoon. If you don't have these items, you can do the experiment with me. If you would like to do the experiment, you need to make sure there is an adult to help you. Pause the video now, and go and get them. I'm wearing my lab coat because this experiment can get a little bit messy. You might also want to wear something to protect your clothes. We're going to look at the mixing of oil and water. I have two liquids, oil and water. Let's see what happens when I mix them. That's interesting. The oil floats on the top. Can you see that? The two liquids are still separate. They didn't mix. Did that happen in your experiment too? Let's try giving them a stir, and see what that happens. They still don't mix. The oil is still at the top, and the water is still at the bottom. These two liquids, oil and water, don't mix. There is a special scientific word for liquids that don't mix. These liquids are called immiscible. My turn. Immiscible. Your turn. Good pronunciation. These liquids don't mix. They are immiscible. What do we call two liquids that do not mix? Immiscible. Now let's see what happens when we add some washing-up liquid. Before I add the washing-up liquid, the oil and the water do not mix. Which scientific word can I use to describe that? Oil and water are immiscible because they don't mix. Now I'm going to add some washing-up liquid. Let's see what happens. Give it a stir. Can you see what's happening? The oil and the water are now mixed. We've not got two separate layers anymore. Liquids that mix are called miscible. My turn. Miscible. Your turn. What do we call two liquids that do mix? Miscible. Isn't it interesting that oil and water don't mix by themselves, but they do mix when we add washing-up liquid? That's why we need to use washing-up liquid when we clean our pots and pans. The washing-up liquid makes the oil and water miscible so that we can remove it from the pan. Next time you're washing up, you can explain that we use soap to make the oil and water miscible. Isn't that interesting? Let's practise. Why do we have to use soap when we're washing up? We use soap when we're washing up to make the oil and water miscible, so we can remove it from the pan. What did the word miscible mean? Miscible means that two liquids can mix. Great. Let's recap our knowledge. You have four questions to answer. I'm going to read them to you and then give you time to pause the video. Question one, what happens when you mix oil and water together? Question two, what is it called when two liquids do not mix? Question three, what happens when you add soap? Question four, what is it called when two liquids do mix? Pause the video, and answer the questions. Press play when you're ready to continue. Question one, oil and water do not mix. There is a layer of oil on top of a layer of water. Question two, two liquids that do not mix are called immiscible. Question three, when soap is added, the oil and water mix together. They are no longer in separate layers. Question four, two liquids that can mix are called miscible. What an exciting lesson that was. It is great when we learn things about the world around us. Isn't it? Make sure you have a go at the quiz to recap your knowledge. See you next time!

In this lesson, we will learn what makes a substance a formulation. We will identify some common formulations and investigate what happens when formulations are scaled up or down.

What is a formulation?

﻿Hello there, how are you today? Are you ready for our lesson? My name is Ms. Couves, and I'm going to be teaching you science today. I am so excited because science is my favourite subject. Today, we are going to be learning about formulations. Formulations are so important. They help us to make all sorts of things, including paint, medicines and squash. Let's get started. Today, we're going to start by recapping on knowledge from previous lessons. Then we are going to learn about what a formulation is, how we can make more of a formulation. And finally, we're going to end by doing an investigation. In this lesson, you're going to need, an exercise book or paper, a pencil and if you want to do our experiment, you'll also need some squash, a cup, some water, and a spoon. You will also need an adult to help you. If you don't have any of these things, pause the video and go and get them now. Let's start by recapping our knowledge. Pause the video and identify each state of matter from the diagrams. Press play when you're ready to continue. Well, how were the particles arranged in a solid? Particles in a solid arranged in audit rows? And they're touching. How are particles arranged in a liquid? Particles in a liquid are arranged randomly, but still touching. How are particles arranged at a gas? Particles in a gas are moving fast and they're not touching. Point to the diagram that shows a pure gas. How do you know that this is a pure gas? A pure gas only contains one type of particle. The diagram on the left shows a pure gas because it only contains one type of particle. The diagram on the right is an impure gas because it contains more than one type of particle. How do I know that there is more than one type of particle? There are two different colours used to represent two different types of particles. Going to the diagram that shows a pure metal, how do you know that this is a pure metal? We know that this is a pure metal because it only contains one type of acid. Point to the diagram that shows an alloy. How do you know that this is an alloy? This is an alloy because it contains two types of particles. What do you know about the strength of alloys compared to a pure metal? Alloys are much stronger than pure metals. Can you remember an example of any alloys? Bronze is an alloy of copper and tin. Steel is an alloy of iron and carbon. When we add water and oil together, they don't mix. What do we call two liquids that do not mix? Two liquids that do not mix called immiscible. What happens when we added soap? They did not mix. What is the scientific word for liquids that did not mix? Sorry, when we added soap, they did mix. What is the scientific word for liquids that did mix? Miscible, miscible liquids are liquids that can mix together. Now we're going to learn about formulations. Formulations are mixes made up with a specific ratio of substances. My turn, formulations are mixtures made up with a specific ratio of substances, your turn? Here are three examples of formulations. What is a formulation? A formulation is a mixture made up with a specific ratio of substances. Other three examples are squash, paint and medications. For each of these examples, they need to contain exactly the right amount of each substance or they will not have the right properties. The squash might be too sweet, the paint the wrong colour, and the medications might not work if the ratio of substances isn't the same. One needs to be the same in a formulation. A formulation needs to have the same ratio of substances. Is this a formulation? When making a cake, you always use the same amount of butter, flour, and eggs. What do you think? This is a formulation. When you make a cake, you always use the same amount of sugar, butter, flour, and eggs. If you use a different amount, the cake wouldn't taste the same. Is this a formulation? When making washing up mixture, I always use the same amount of washing up liquid and water. What do you think? This is a formulation because when I make washing up mixture, I always use the same amount of washing up liquid and water. What needs to be the same in a formulation? A formulation needs to have the same ratio of substances. Let's test our knowledge. I'm going to read you all the questions and then tell you to pause the video to complete them. Question one, what is a formulation? Question two, why is a cake a formulation? Question three, what would happen if you change the amounts of each substance in a formulation? Question four, does the amount of each substance need to be the same as each other? Pause the video, press play when you're ready to continue. A formulation is a mixture made up of specific amounts of each substance. A cake is a formulation because you use the same amounts of flour, eggs, sugar, and butter to make the same type of cake. If you change the amounts of each substance in a formulation, it would change the properties of the formulation. The amounts of each substance in a formulation do not have to be equal, but they must be the same every time. Pause the video, to tick and or fix your answers. Now we're going to think about scaling formulations. That means making larger or smaller amounts. Well, do we know about the amount of each substance in a formulation? We know that the amount of substance in a formulation needs to have the same ratio. Lets imagine a cake. Instead of making one cake, I want to make four cakes. What do I need to do to each of my ingredients? I need to use four times as much as everything. That's four times as much flour, four times as much sugar, four times as much butter and four times as many eggs. That way I will have the same ratio of ingredients, but more cakes. My recipe gives me the ingredients for one cake. I want to make four cakes, what should I do? Option one, use the same amounts of each ingredient. Option two, use four times as much of each ingredient. Option three, use four times as much sugar and butter, but the same amount of flour and eggs. Option four, use two times as much of each ingredient. Which one do you think? To make four times as many cakes, I need to use four times as much of each ingredient. So option two is the correct answer. Let's imagine I only want to make half a pot of paint. What do I need to do to all of the substances that make a pot to paint? When I wanted to make four times as many cakes, I had to times all of the ingredients by four, if I only want to make half the amount of paint, I need to half the amount of all the substances to keep the ratio the same, but only make half as much paint. My instructions give me the substances for one pot of paint. I want to make half a pot, what should I do? Option one, use the same amount of each substance, option two, use two times as much of each substance, option three, use half the amount of colour dye but the same amount of water. Option four, use half as much of each substance. What do you think? Option four, I need to use half as much of each substance, because I need to keep the ratio of substances the same, that make half as much. Let's investigate formulations. If you want to have a go, you need to pause the video now and go and get an adult to help you. For this experiment, you need a glass of water, some squash, an empty cup and a spoon. Press play when you're ready to continue. If you don't have the materials for this experiment, you can just follow along with me. In order to do our experiment, you need to copy this table into our notes so that we can record our results. Pause the video now to draw the table into your notes. Press play when you're ready to continue with our experiment. In our experiment, we're going to use a dessert spoon to measure out the amounts of squash and water into the cups. We're then going to put the cups next to each other and compare the colour of the mixtures. Then we're going to taste small amounts of the mixture to see how they taste. So I'm going to do my experiment. I've got my four cups in front of me and I've got some water and some squash. I'll start by pouring the squash into a cup, so it's easier for me to use. The table for cup number one. How many spoonfuls of squash do I need? I need one spoonful full of squash. This cup number one, I need to add one spoonful of squash. How many spoonfuls of squash do I need for cup number two? I need two spoonfuls of squash. One, two, can you see how I'm measuring the squash really carefully each time to make sure I only put one spoonful in or two spoonfuls. Now let's look at the cup number three. How many spoonfuls of squash do I need for cup number three? I need three spoonfuls of squash for cup number three. One, two, three. Therefore, one spoonful in cup one, two spoonfuls in cup two, and three spoonfuls in cup three. How many spoonfuls do I need in cup number four? I need five spoonfuls in cup number four. One, two, I may need to fill the spoon the same amount each time. Three, four, Five. So I've added all of my squash now to each of my cups. So now I'm going to add the spoonfuls of water to each cup. So go back to this cup number one, how many spoonfuls of water do I need to add to cup number one? I need to add five spoonfuls of water to cup number one. So let's have a go. Remember to fill the spoon in the same amount in each time. One, two, three, four, five. Now I've added all of the ingredients in my formulation, I'm going to swirl it around to make sure it mixes well. Can you remember the name for two liquids that mix? Two liquids that mix are called miscible liquids. Let's try cup number two. How many spoonfuls of water do I need for cup number two? I need 10 spoonfuls of water for cup number two, ready? One, two, three, four, five, six, seven, eight, nine and ten. What do I need to do after I added the water? I need to swirl it around to make sure that the liquids get evenly mixed up. Great, cup number three. How many spoonfuls of water does cup number three need? 15 spoonfuls, right, ready? One, two, three, four, five six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen What do I need to do? I need to swirl it. Okay, cup number four. How many spoonfuls of water does cup number four need? One spoonful of water. One. What do I need to do? I need to swirl it. Okay, let's compare our formulations. So we have got cups number one, two and three. What do you notice about the colour of cups one, two and three? Sorry one and two? The colour looks the same, doesn't it? They have to be exactly the same colour. Let's compare cup number two and cup number three. What do you think about the colour of cup number two and cup number three? Again, they look like they're the same colour. Cup number two and cup number three and cup number one, all look to be the same colour. Let's compare cup number two and cup number four. What do you notice about cup number four, compared to cup number two? Cup number four is much darker than cup number two. Let's record that in our table. Cup number one, two and three were the same colour and cup number four was darker. Pause the video to record your results, and press play when you're ready to continue. Now we're going to taste our cups. We're going to start with cup one. Then cup two, then cup three, then cup four. I want you to decide whether the cups tastes the same or different. Cup number one, cup number two, cup number one and cup number two taste the same. Lets try cup number three. What do you predict based on the colour? Do you think that cup number one and number three are going to taste the same or different? Cup number three tastes the same as cup number one and cup number two. Is that what you predicted? It's what I predicted. I thought that because the colour was the same, they would also taste the same. Let's try cup number four. Are we expecting this one to taste the same? Aaw cup number four is really, really, really sweet. It tastes like there's so much squash in there. So cup number one, cup number two and cup number three, all tasted the same. But cup number four, was way too sweet. Let's have a look at our table. Cup number one cup, number two and cup number three, all have a ratio of one spoonful of squash to five spoonfuls of water. For cup two, we times all of the ingredients by two, and for cup three, we times all of the ingredients by three. So they have the same formulation, but there's just more of it. The cup number four, we used a completely different ratio. We use more squash and less water. And so it didn't taste the same and it didn't have the same colour. What needs to be the same in our formulation? We need to have the same ratio of substances in our formulation. Let's recap our knowledge using some conclusion questions. What did you notice about the colour of one, two and three compared to number four? What did you notice about the taste of one, two and three compared to number four? Why do you think this is the case? If you use squash that is double concentrate, what will you have to do differently when you use it? Pause the video to answer the questions. Press play when you're ready to continue. The colour of cups one, two, and three was lighter than cup four. Question two, the taste of cups, one, two and three was weaker than cup four. Question three, cups, one, two, and three, have the same ratio or formulation, whereas cup four had more squash and less water. Question four, if you use double concentrate squash, you would need to use half the amount of squash to get the same flavour. Pause the video to tick or fix your answers. Thank you so much for participating in our lesson today. I had a really great time. I hope you enjoyed our investigation about squash. Remember to take the quiz at the end of the lesson, to check your knowledge. See you next time.

In this lesson we will learn about four ways that mixtures can be separated, including using magnets; evaporation, filtration and sieving.

How can we separate mixtures into pure substances?

﻿Hello again, are you excited for our lesson today? I am so excited, as today we're going to be looking at how we can convert mixtures into pure substances. I'm going to be showing you so many ways of separating mixtures that I've decided to wear my lab coat for the whole time. This is such an important skill for scientists. And at the end, you're going to be an expert. Are you ready to get started? Right, let's go. Today, we're going to start by recapping our knowledge of mixtures so far. Then we're going to think about how we can separate mixtures of solids, mixtures of solids and liquids and mixtures of solids and liquids, where the solid is soft. We are going to make our own mixture and think about how we could get pure substances back. For this lesson, you're going to need an exercise book or paper and a pencil. If you don't have one of these items, pause the video now and go and get them. If you would like to have a go at our experiment, you will also need some salt, some water and a spoon and an adult to help you. Ready? Let's start by recapping our knowledge. First, we learned about how particles are arranged in solids, liquids and gases. Can you remember how they are arranged? Pause the video now and draw a diagram to represent the particles in each of the three states of matter. Press Play when you're ready to find out the answer. The particles in a solid are arranged in ordered rows and touching. Can you remember how the particles in a solid move? They vibrate on the spot. Show me the particles in a solid. Great, they vibrate on the spot. The particles in a liquid are touching, but in a random arrangement. How did the particles in a liquid behave? The particles in a liquid can slide past each other. Show me the particles in a liquid. Right. The particles in a gas are really far apart and moving really fast. Show me the particles in a gas. The particles in a gas are moving really, really fast and they're not touching. Point to the diagram that represents an impure gas. How'd you know? The diagram on the right shows an impure gas, because an impure gas has more than one type of particle. The particle on the diagram on the right has more than one type of particle, because there are two different coloured particles in the diagram. Point to the diagram that represents a pure metal. How do you know? The two diagrams on the left of the screen represent a pure metal, because they only contain one type of particle. Point to the diagram that represents an alloy. How do you know this is an alloy? This diagram contains two different types of particles. Therefore, we know that it's a mixture. An alloy is a mixture made up of metals. Now, we're going to think about how we can separate solids. We're going to start with a experiment where we separate sand and iron into sand particles and iron particles. So, I have my sand particles, I have my iron particles. I'm going to mix them together. Here's my sheet of paper. I'm going to mix my sand particles with my iron particles. Can you see that they're mixed together? Now, I want to separate my sand particles and my iron particles. How can I separate my sand particles from my iron particles? I'm going to use a magnet. I can use a magnet, because iron is magnetic, but sand isn't. Let's have a go. I'm going to put my magnet underneath. Can you see how it's picked up the iron particles and is pulling them out? There, can you see that it's collecting the iron particles only and leaving the sand particles behind? If I keep doing this, I can collect all of the iron particles in the mixture and separate them from the sand particles so that I have a sample of pure sand and a sample of pure iron. So here I have my iron particles and here I have my sand particles, they're separate. Why could I use a magnet to separate iron and sand? You could use a magnet to separate iron and sand, because the iron is magnetic and the sand isn't. Which two particles are present in the mixture? In the mixture there were sand particles and iron particles. Now we have pure sand and pure iron. How many particles are there in the pure sand? How many types of particles are there in the pure sand sample? There's only one type of particle, sand particles. How many particles are there, types of particles are there in the pure iron sample? Just one, iron particles. After using the magnetic to separate the iron and the sand, we have pure sand and pure iron. Pause the video and have a go at drawing all three particle diagrams to represent the mixture, pure iron and pure sand. Press Play when you're ready to continue. For the mixture of sand and iron there were two types of particles, sand particles and iron particles. So we had two different coloured particles in our diagram. For our pure samples, we only had one type of particle. Throughout our experiment, everything was a solid, so we've arranged our particles so that they're touching and in ordered rows. Let's test our knowledge. I'm going to read you all three questions and then give you a chance to write the answers down. Number 1, why is the mixture of sand and iron impure? Number 2, why was the sand sample at the end pure? Number 3, why could we use a magnet to separate sand and iron? Pause the video and complete the questions. Press Play, when you're ready to continue. Number 1, the mixture of sand and iron contain two different types of substance and a pure substance can only contain one. the sand sample at the end was pure, because it only contained sand particles and the iron particles had been removed. Number 3, a magnet can be used to separate iron and sand, because iron is magnetic and sand is not. Pause the video to tick or fix your answers? Press Play, when you're ready to continue. Now, we're going to think about separating a solid and a liquid. In this experiment, we're going to look at pasta and water. Here I have my mixture of pasta and water. Can you see the pasta at the bottom and the water at the top? I want to separate my mixture of pasta and water. What do you think I could use to separate a mixture of pasta and water? I'm going to use a sieve to separate my pasta and my water. The sieve can be used to separate pasta and water, because the holes in the sieve are small enough for the water to go through, but big enough... Sorry, big enough for the water to go through, but small enough to stop the pasta from going through. Let's watch. So I'm going to pour my liquid through. Can you see that the water is now in the jug below and my pasta is being stayed in the sieve? That's because the pasta is too big to fit through the tiny holes in the sieve, but the water can fit through. So now we have a pure sample of pasta and a pure sample of water. Let's have a look at another solid. This time, I have a mixture of sand and water. Can you see the sand is collecting at the bottom? Particles are much smaller than the pasta particles. Do you think that the sand particles will be small enough to fit through the sieve? The sand particles are small enough to fit through the sieve. So we need to use something different. We need to use filter paper and a funnel. This is a funnel, and this is a piece of filter paper. The filter paper has really tiny holes. The holes are so small that the water particles can fit through, but the sand particles will get trapped. Why can filter paper be used to separate sand and water? Filter paper can be used to separate sand and water, because the water particles can fit through the filter paper, but the sand particles can't. So I've just placed my filter paper in the bottom of my funnel and I'm going to pour my sand and water mixture into the filter paper. Remember, we're expecting the water particles to go through and the sand particles to not. Poured too much in. So we can see that the water is going through. Can you see it dripping out the bottom? The water particles are small enough to fit through the tiny holes in the filter paper. Let's see what happens when the sand particles are there. Okay, so now I've got sand particles in the filter paper and water particles dropping through. Why can't the sand particles pass through the filter paper? The sand particles can't pass through the filter paper because the sand particles are too big to fit through. The water particles can fit through the filter paper because they are small enough to fit through the tiny holes in the filter paper. So when this is finished, we'll have all of our sand particles in the filter paper and all of our water particles in the jug below. So now we have a pure sample of sand and a pure sample of water. How many particles are there in the pure sample of sand? There's one type of particle in the pure sample of sand. How many types of particles are there in the pure sample of water? There is one type of particle in the pure substance of water. So now we've learned how to separate sand and water and pasta and water. Let's have a go at recapping our knowledge. I'm going to read you these four questions, then I'm going to give you some time to pause the video and answer them. Why was the mixture of sand and water impure? 2, why could pasta be removed from the water using a sieve? 3, why could sand not be removed from the water using a sieve? Number 4, why was the filter paper better for removing sand from water? Number 5, why was the sieve better for removing pasta from water? Pause the video now to complete the questions. Press Play when you're ready to continue. Question 1, the mixture of sand and water was impure, because it contained two different types of substance. Number 2, the pasta could be removed from the water with using a sieve, because the pasta was too big to fit through the holes in the sieve. Number 3, sand could not be removed from the water using a sieve, because it was small enough to fit through the holes in the sieve. 4, filter paper was better for moving sand, because the sand could not fit through the holes in the filter paper. Number 5, the sieve was better for removing pasta from water, because the water could pass through faster. Pause the video now to tick and fix your answers. Now, we're going to make a solution together. A solution is a mixture of a liquid where the solid dissolves. If you would like to have a good making a solution, you need to get yourself some salt, some water and a spoon. You also need an adult to help you. Pause the video and go and get them if you would like to have a go. If not, you can watch me do the experiment. I'm going to make a solution of salt and water. When we mix salt and water, the salt dissolves. My turn, dissolves. Your turn... Great. We can see the salt has dissolved, because we won't be able to see it anymore. Here I have some salt. Salt is a white solid. I also have some water. I'm going to add my salt to the water and see what happens. When I add my salt to the water and stir, it looks like the salt disappears. Actually, what's happening is the salt is breaking down into tiny, tiny, tiny particles and the water is surrounding it so that we can no longer see it. If we keep mixing all of the salt will dissolve. Now my particles are well and truly mixed up. The salt has dissolved. If a solid can dissolve in a liquid, it is called soluble. My turn, soluble. Your turn... Is salt a soluble solid? Salt is a soluble solid, because all of my salt has dissolved. Now, how do I get my salt back? Can I use a magnet? I can't use a magnet, because salt and water are not magnetic. Can I use a sieve? I can't use a sieve, because the salt particles are really, really tiny. What about filter paper? I can't use filter paper, because again, I can't see the solid, the particles are really tiny. I need to use something different I need to use evaporation. My turn, evaporation. Your turn... Great, we need to use evaporation. I'm going to heat the water up, so that it evaporates. You shouldn't do this at home, because it can be a bit dangerous. So just watch me. I've poured my salty water into a glass bowl and I'm putting my glass bowl on top of some boiling water. I'm doing that so that I can heat the water in my salt water solution slowly so that I can evaporate it, leaving behind salt particles. Can you see the water boiling? The reason we can use evaporation to separate salt and water is because water evaporates at a much lower temperature than salt. Water has a low boiling point and salt has a high boiling point. So when we heat the water, all of the water will evaporate leaving behind the salt. Why can we use evaporation to separate salt and water? We can use evaporation to separate salt and water, because salt has a much higher boiling point than water. So all of the water will evaporate leaving behind the salt. If you watch carefully, around the edge, you'll see the salt starting to form. Look it's boiling really vigorously now. We should be able to start seeing some salt soon. Can you see the salt that is formed now the water has evaporated? We're left with these crystals of salt in our bowl. Why could we use evaporation to separate salt and water? We could use evaporation to separate salt and water, because salt has a much higher boiling point than water. Let's have a go at drawing the particle diagrams for salty water, the solution of salt and water, salt and water. Have a think. How many different types of particles are there in salty water? How were the particles arranged? Pause the video and draw the diagrams. Press Play, when you're ready to continue. The salty water has two types of particles, salt particles and water particles. Pure salt has got just salt particles and water has got just water particles. Let's test our knowledge. Question 1, why was the mixture of salt and water impure? Question 2, why could we not use filtration to separate salt and water? Question 3, why could we use evaporation to separate salt and water? Pause the video now and answer the questions in full sentences. Press Play when you're ready to continue. The mixture of salt and water was impure, because it contained two different substances. Filtration could not be used to separate salt and water because when the salt particles dissolve, they are small enough to fit through the holes in the filter paper. Evaporation could be used to separate salt and water because salt has a much higher boiling point than water. So the water evaporates leaving behind the salt. Pause the video to tick and fix your answers. Press Play when you're ready to continue. How can we separate sugar and water? Sugar dissolves in water, it is soluble. Option 1, using a magnet, option 2, using a sieve, option 3, using filter paper, or option 4, evaporation. What do you think? We need to use evaporation to separate sugar and water, because sugar dissolves in water. How could we separate iron and wood chips? Iron and wood chips are both solids. Iron is magnetic. Option 1, use a magnet, option 2, use a sieve, option 3, use filter paper, or option 4, evaporation. We can use option 1, a magnet, because iron is magnetic and wood chips are not. Last question. How could we separate pebbles and water? Option 1, using a magnet, option 2, using a sieve, option 3, filter paper, or option 4, evaporation. We would separate pebbles and water using a sieve, because the pebbles would be too big to fit through the tiny holes in the sieve. You've done an excellent job in our lesson today, we have learnt so much about separation. Make sure you do the quiz to show all that you have learned. See you next time.

In this lesson we will learn about how to separate soluble and insoluble solids from water.

How can you separate a mixture of sand, salt and water?

﻿Hello again. My name's Ms. Couves and I am really excited to be your science teacher today. Today, we're going to be investigating seawater. Have you ever been to the beach? What was it like? Did you go in the sea? Did you accidentally taste the seawater? What did it taste of? Did it taste salty? That's because seawater contains a lot of salt. We're going to look closely at the particles in seawater together. Let's get started. Today, we will start by recapping our knowledge so far. Then we will talk about dissolving and soluble and insoluble solids. We are then going to make our own seawater sample and plan how we can separate it. In this lesson, you will need an exercise book or paper and a pencil. If you don't have one of these items, pause the video now and go and get them. If you would like to make your own sample of seawater, you will also need some salt, some sand, some water, and a spoon. You'll also need an adult to help you. Right, let's recap our knowledge. Pause the video and complete the slide to say which state of matter each diagram represents. Underneath the diagram, you can write a description of the arrangement of particles in solids, liquids, and gases. Pause the video and press play when you're ready to continue. The particles in a solid, which is the left-hand diagram, are arranged in ordered rows. They are touching and their particles vibrate on the spot. Particles in a liquid are touching each other but are arranged randomly. Particles in a gas are far apart and moving really fast. Point to the diagram which shows a pure gas. The diagram on the left shows a pure gas. How do we know that this is a pure gas? We know that it's a pure gas because it only contains one type of particle. Pause the video and complete this slide. Press play when you're ready to continue. What is an alloy? An alloy is a mixture of metals. The two diagrams on the left-hand side show the particles in a pure metal. How do we know that these are pure metals? We know that they're pure because they only contain one type of atom. The diagram on the right shows an alloy. How do we know that this is a mixture? We know this is a mixture because it contains more than one type of particle. Can you remember an example of an alloy? Bronze is an alloy of tin and copper, and steel is an alloy of carbon and iron. Can you remember the definition of a formulation? A formulation is a mixture made with a specific ratio of substances. Is a cake a formulation? A cake is an example of a formulation. If you were to use a different ratio of ingredients, it wouldn't taste the same. If I wanted to make four cakes, what do I need to do differently? I need to multiply all the ingredients in my recipe for one cake by four. This keeps the ratio the same, but makes more cake. We're now going to learn about dissolving. I am going to dissolve some salt in water to make salty water. Watch carefully to see what happens. Here are my large particles of salt. When put them in and I stir, the particles are going to break down and get smaller and smaller and smaller, and then they're going to be surrounded by water particles, which means we'll no longer be able to see them. The solid that are, is dissolved in a liquid is called a solute. Solid that can dissolve in a liquid is called a solute. What was the solute in our experiment? The solute in our experiment was salt because salt was dissolved in water. A solvent is a liquid a solid dissolves in. What was the liquid a solid dissolved in in our experiment? Water. Water is an example of a solvent because the solute, such as salt, can be dissolved in it. The solution we have now is made of salt particles and water particles. When a solute has been dissolved in a solvent, it's called a solution. What two particles are in our solution? The two particles in our solution are salt particles and water particles. Have a go at drawing the particle diagram for saltwater. Press play when you're ready to continue. Check your answer against my answer. Your particle diagram should have two different types of particles, salt particles and water particles. Salt dissolves in water. Salt is called, option one, a solution, option two, a solvent, option three, a solute, or option four, a formulation. What do you think? Salt is an example of a solute. Salt dissolves in water. Water is called a solution, option two, a solvent, option three, a solute, or option four, a formulation. What do you think? Option two, salt is a salt, sorry, water is a solvent, salt is a solute. Salt dissolves in water. The mixture produced is called, option one, a solution, option two, a solvent, option three, a solute, or option four, a formulation. What do you think? The mixture produced is called a solution. A soluble solid dissolves in water. My turn, soluble, your turn. An insoluble solid does not dissolve in water. My turn, insoluble, your turn. We know that salt is soluble in water because it forms a solution. Let's see if sand is soluble or insoluble. What happens when I add sand to water? This is the cup that I placed my salt into. We can see that salt has formed a solution because we can no longer see the salt. I'm going to add sand to this cup of water. What do you think is going to happen? Sand does not dissolve in water. Is it soluble or insoluble? Sand is insoluble because it does not dissolve in water. A soluble solid is a solid that can dissolve in a liquid to form a solution. Examples are sugar and salt. An insoluble solid is a solid that cannot dissolve in liquid to form a solution. Examples include rocks and sand. Pause the video and write down the definition of soluble and insoluble. Press play when you're ready to continue. A soluble solid can be separated by evaporation. My turn, soluble solids are separated by evaporation. Your turn. An insoluble solid is separated by filtration or sieving. My turn, an insoluble solid is separated by filtration or sieving. Your turn. When would I use filtration instead of sieving? I'd use filtration instead of sieving if the particles of solids were very small, like sand, because the particles of sand could pass through the holes in the sieve. Let's recap our knowledge. I'm going to read the four questions to you and then give you a chance to pause the video and answer them in full sentences. Sugar is soluble in water. Will sugar dissolve in water? Question two, give two examples of insoluble solids. Question three, how can a soluble solid be separated from a liquid? Question four, how can an insoluble solid be separated from a liquid? Pause the video now and answer the questions in full sentences. Press play when you're ready to continue. Question one, sugar will dissolve in water because it is soluble. Question two, two examples of insoluble solids are rocks and sand. Question three, a soluble solid is separated from a liquid using evaporation. Question four, an insoluble solid is separated from a liquid using filtration or sieving, depending on how big the particles are. Pause the video to tick or fix your answers. Press play when you're ready to move on. Now we're going to make some seawater. If you would like to have a go at making some seawater, you need to get some salt, some sand, some water, a spoon, and an adult to help you. Pause the video and go and get them now. Alternatively, you can watch me do the experiment. Press play when you're ready to start. Seawater is a mixture of sand, salt, and water. We are going to make our own sample of seawater by adding sand, salt, and water. We're going to start by adding salt. Here is my water. I'm going to add salt. Is salt soluble or insoluble? Salt is soluble. Does that mean it will dissolve or it won't dissolve? It will dissolve. Let's watch. Can you see how the particles are being broken apart and surrounded by water molecules? What do I need to add to my seawater now? I need to add some sand. Is sand soluble or insoluble? Sand is insoluble. Does that mean it will dissolve in water or it won't dissolve in water? Let's see. Sand is insoluble, so it doesn't float, doesn't dissolve in water. It sinks to the bottom. Can you see the sand? Here we have our seawater. It contains three types of particles. What are they? The three types of particles in our seawater are sand, water, and salt. Now let's imagine we've taken our sample of seawater from the sea and we want to separate it into pure water, pure salt, and pure sand. What could we do? Have a think. Which solid is soluble? Which solid is insoluble? How can I separate sand? How can I separate salt? In step one, we're going to remove the sand. Is sand soluble or insoluble? Sand is insoluble. How do we remove an insoluble solid from a liquid? We use filtration to remove an insoluble solid from a liquid, so our step one will be filtration. In step two, we are going to remove salt. How do we remove a soluble solid from a liquid? To remove a soluble solid from a liquid, we use evaporation. Let's test our knowledge. I'm going to read you the six questions, then you can pause the video and answer them in full sentences. Question one, which solid in the seawater mixture was insoluble? Question two, how was the insoluble solid separated? Question three, draw a particle diagram to represent the pure sand that was separated. Question four, which solid in the seawater mixture was soluble? Question five, how was the soluble solid separated? And question six, draw a particle diagram to represent the pure salt that was separated. Press play when you're ready to continue. The insoluble solid in seawater is sand. The insoluble solid, sand, was separated by filtration. Number four, the soluble solid in seawater is salt. Five, the soluble solid, salt, was separated by evaporation. Pause the video to tick or fix your answer. Well done today, you've done so much learning. We made our own seawater solution and worked out how we could make it back into pure substances. Make sure you have a go at the quiz to check your knowledge. See you next time.

In this lesson, we will plan and evaluate a method to separate soil and gravel from river water.

How can we separate river water into separate substances?

﻿Hello again. How are you? My name is Ms. Couves, and this is our last lesson in our unit on separating mixtures. We have been working so hard in this unit, and we have learnt so much. Today, we are going to be thinking about a big problem that scientists have. How can we make water safe to drink? Why do you think it's important to scientists to know how to make water that is safe to drink? Today, we are going to think about river water and how we can separate it into separate substances. Here I have my own sample of river water. You should be able to see that there's some stones, some soil, and some water. We're going to think about how we can separate it. Ready? Let's go. Today, we will start by recapping our knowledge from this unit. Then we will think about the job of an environmental scientist. Then we will plan an investigation to separate a sample of river water. And then we will evaluate our investigation. For this lesson, you will need an exercise book and paper and a pencil. If you don't have one of these items, pause the video now and go and get them. Press play when you're ready to continue. Let's recap our knowledge. Can you remember which of the states of matter these diagrams represent? Pause the video now and write them down. Can you annotate your diagram with how the particles behave? Press play when you're ready to continue. The particles in a solid are in ordered rows. They're also touching. Particles in a solid vibrate on the spot. Show me a solid particle. Great. Particles in a liquid are touching, and they are randomly arranged. Particles in a liquid can slide past each other. Show me particles in a liquid. Great. Particles in a gas are moving fast in all directions. Show me particles in a gas. Great. Which diagram shows an impure gas? The diagram on the right shows an impure gaps because there are two types of particle. How do I know that there are two different types of particle? Because there are two different colours. Pause the video to complete this slide to identify which samples are pure metals and which one is an alloy. What is an alloy? An alloy is a mixture of metals. The two diagrams on the left-hand side show particles in a pure metal. How do we know that? We know that the diagrams on the left show pure substances because they only contain one type of particle. The diagram on the right shows a mixture. How do we know the diagram on the right shows a mixture? We know that the diagram on the right shows a mixture because there are more than one type of particle. The diagram on the right shows an alloy. Can you remember an example of an alloy? Bronze is an alloy of tin and copper. And steel is an alloy of carbon and zinc. Salt dissolves in water. Is salt soluble or insoluble? Salt is soluble because it dissolves in water. When salt dissolves in water, the salt crystals are broken apart into tiny particles, which are surrounded by water particles. So we can't see them anymore. Is sand soluble or insoluble? Sand is insoluble because it does not dissolve in water. The particles collect at the bottom of the container. A soluble solid can dissolve in a liquid to form a solution. Examples are sugar and salt. And we separate soluble solids using evaporation. Insoluble solids cannot dissolve in water to form a solution. They include rocks and sand. We separate insoluble solids by using filtration or sieving. Now we're going to learn about environmental scientists. An environmental scientist works to protect the environment and human health. They measure the amount of pollution in the air and in rivers. Pause the video and write down what an environmental scientist does. An environmental scientist works to protect the environment and human health. They measure the amount of pollution in rivers and in the air. I have a sample of river water. In our investigation today, we are going to be environmental scientists and plan how to make this river water pure. River water is made up of soil, gravel, and water. Have a look at my sample. Can you see the gravel and the soil? What states of matter are these substances in? The soil and the gravel are solids, and the water is a liquid. Is this sample pure or impure? The sample is impure because there is more than one type of particle. What types of particle do we have? We have gravel particles, water particles, and soil particles. Are the solids soluble or insoluble? We've got two insoluble solids: soil particles and gravel particles. What's the difference between the two insoluble solids? One of the solids is very big. And one of the solids is very small. That will help us to separate them. How do we separate insoluble solids from a liquid? We separate insoluble solids from a liquid using sieving or filtration. What do you notice about the size of gravel compared to soil? The soil is much smaller than the gravel particles. Now we're going to plan our experiment. Which techniques do we need to use in order to separate our river water? Filtration, sieving, or evaporation? What do you think? We need to use filtration and sieving. We don't need to use evaporation, because we don't have a soluble solid. Which particle is going to be removed by sieving? The gravel particles are going to be removed by sieving. Which particle is going to be removed by filtration? The soil particles are going to be removed by filtration. Write a list of all the equipment that you will need. Then number your steps in your method, and start each step with a verb. For example, place the filter paper in a funnel and place the funnel into a cup. Pause the video and write the method for the filtration and sieving. Press play when you're ready to see my method. In my method, we're going to start with filtering. We're going to place the filter paper into the funnel and place the funnel into the cup. Pour the river water sample into the filter paper, and then place the insoluble sample into a sieve. We'll shake the sieve until the sand particles and gravel particles are separated. While we're doing our experiment, I want to think about how we can make it better. We're going to write down next to our method if we think of something that can make it better. Right, let's have a go at our experiment. What was the first step in my method? The first step in my method was to place the filter paper into the funnel. So I put my funnel into a cup, and I'm putting my filter paper into my funnel. This is not an experiment that you should try at home. I'm now going to pour my river water sample into the funnel. I poured a little bit too much in there and some of the soil has ended up in the sample underneath. I might need to add to my method, pour the river water slowly into the filter paper to improve it. When I had filtered all of the sample, I placed my insoluble solids into the sieve, and I'm going to shake my sieve until the soil particles and gravel particles are separated. Here is my pure gravel sample after the sieving. Can you see that there are still some bits of soil in my sample? Why do you think there are still some bits of soil in my sample? These bits of soil are too big to fit through the holes in the sieve. So I need to use a sieve with bigger holes. That's two improvements we could make to this method. Have you written them down? Firstly, we needed to pour the river water in slowly to prevent overflowing the filter paper. And secondly, we needed to use a sieve with bigger holes. Now we're going to evaluate our investigation. We need to evaluate our method by saying two things that went well and one thing that we could have done better. Pause the video and write down two things that went well in our experiment and one thing that could have gone better. Two things that went well in our experiment were that we did manage to separate the water from the soil and we did manage to separate the gravel from most of the soil particles. One thing that could have gone better is that we could have used a sieve with bigger holes to separate the soil and the gravel. Pause the video and redraft your method to make it better. Press play when you're ready to continue. If you'd like to, please ask your parent or carer to share your work on Instagram, Facebook, or Twitter, tagging @OakNational and #LearnwithOak. I've had so much fun learning about separating mixtures with you. I hope you have too. Make sure you do the final quiz to check your knowledge of everything from this unit. Bye!

Unit Overview: Separating mixtures

National Curriculum

Unit Question

Lessons: