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Unit Quiz: Atomic Structure

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Q1. If the half-life of a substance is 11 hours, and the original count rate is 800 Bq, what will be the count rate after 22 hours.

Options:

  1. Impossible to tell
  2. 200 Bq
  3. 400 Bq
  4. 100 Bq

Correct Answer:

  1. 200 Bq

Q2. Which of these situations might lead to contamination by radioactive isotopes?

Options:

  1. Having an X-ray
  2. Flying at high altitude in an aeroplane
  3. Using radioactive isotopes in medical diagnostics
  4. Visiting a patient who has had radiotherapy in a hospital

Correct Answer:

  1. Using radioactive isotopes in medical diagnostics

Q3. What is the best definition of 'activity'?

Options:

  1. How much radiation there is
  2. The time taken for half the nuclei to decay
  3. The rate at which a source of unstable nuclei decays
  4. The number of decays recorded each second by a detector

Correct Answer:

  1. The rate at which a source of unstable nuclei decays

Q4. What is the best definition of 'half life'?

Options:

  1. How much radiation there is
  2. The time taken for half the nuclei to decay
  3. The rate at which a source of unstable nuclei decays
  4. The number of decays recorded each second by a detector

Correct Answer:

  1. The time taken for half the nuclei to decay

Q5. What is the best definition of 'count rate'?

Options:

  1. How much radiation there is
  2. The time taken for half the nuclei to decay
  3. The rate at which a source of unstable nuclei decays
  4. The number of decays recorded each second by a detector

Correct Answer:

  1. The number of decays recorded each second by a detector

Q6. What is activity measured in?

Options:

  1. Be
  2. Bq
  3. g
  4. g/s

Correct Answer:

  1. Bq

Q7. If a radioactive sample contained 1600 billion nuclei and its half life was 57 years, after how many years would there be 400 billion nuclei remaining?

Options:

  1. 57
  2. 114
  3. 171
  4. 400
  5. 800
  6. 1200

Correct Answer:

  1. 114

Q8. A radioactive isotope has a half-life of 20 hours. How long will it take for 3/4 of the source to decay?

Options:

  1. 10 hours
  2. 20 hours
  3. 30 hours
  4. 40 hours
  5. 50 hours
  6. 60 hours

Correct Answer:

  1. 40 hours

Q9. What does contamination mean?

Options:

  1. The unwanted presence of materials containing radioactive atoms on other materials.
  2. The process of exposing an object to nuclear radiation.
  3. The process of an unstable nucleus becoming stable.
  4. Keeping safe from radiation.

Correct Answer:

  1. The unwanted presence of materials containing radioactive atoms on other materials.

Q10. What does irradiation mean?

Options:

  1. The unwanted presence of materials containing radioactive atoms on other materials.
  2. The process of exposing an object to nuclear radiation.
  3. The process of an unstable nucleus becoming stable.
  4. Keeping safe from radiation.

Correct Answer:

  1. The process of exposing an object to nuclear radiation.

Q11. What is gamma radiation?

Options:

  1. A high speed electron from the shells
  2. A proton being emitted
  3. A helium nucleus
  4. A wave of electromagnetic radiation from the nucleus
  5. A high speed electron from the nucleus
  6. A neutron being emitted

Correct Answer:

  1. A wave of electromagnetic radiation from the nucleus

Q12. What is alpha radiation?

Options:

  1. A high speed electron from the shells
  2. A proton being emitted
  3. A helium nucleus
  4. A wave of electromagnetic radiation from the nucleus
  5. A high speed electron from the nucleus
  6. A neutron being emitted

Correct Answer:

  1. A helium nucleus

Q13. What is beta radiation?

Options:

  1. A high speed electron from the shells
  2. A proton being emitted
  3. A helium nucleus
  4. A wave of electromagnetic radiation from the nucleus
  5. A high speed electron from the nucleus
  6. A neutron being emitted

Correct Answer:

  1. A high speed electron from the nucleus

Q14. Which is the most ionising radiation?

Options:

  1. Alpha
  2. Beta
  3. Gamma

Correct Answer:

  1. Alpha

Q15. Which is the least pentrating radiation?

Options:

  1. Alpha
  2. Beta
  3. Gamma

Correct Answer:

  1. Alpha

Q16. Which two types of radiation can pass through skin but are absorbed by a thin sheet of aluminium?

Options:

  1. Alpha
  2. Beta
  3. Gamma

Correct Answer:

  1. Alpha
  2. Beta

Q17. Which radiation is the most dangerous at long distances?

Options:

  1. Alpha
  2. Beta
  3. Gamma

Correct Answer:

  1. Gamma

Q18. Which sentence best describes the Plum Pudding Model?

Options:

  1. An atom cannot be divided into anything smaller.
  2. An atom is made of a positive blob with negative electrons in it that can be removed or added to.
  3. An atom is made of a negative blob with positive electrons in it that can be removed or added to.
  4. An atom has a dense positive central nucleus with electrons orbiting in shells.

Correct Answer:

  1. An atom is made of a positive blob with negative electrons in it that can be removed or added to.

Q19. Which TWO of these particles can be found within the nucleus of an atom?

Options:

  1. Protons
  2. Electrons
  3. Ions
  4. Neutrons

Correct Answer:

  1. Protons
  2. Neutrons

Q20. How many neutrons are found in this isotope?

Options:

  1. 22
  2. 26
  3. 48
  4. 70

Correct Answer:

  1. 26

Q21. Which of these best explains an isotope?

Options:

  1. The same number of protons and a different number of electrons.
  2. The same number of electrons and a different number of neutrons
  3. The same number of protons and a different number of neutrons.
  4. The same number of neutrons and a different number of protons.

Correct Answer:

  1. The same number of protons and a different number of neutrons.

Q22. Which of these best describes ionisation?

Options:

  1. An atom becoming charged when it loses an electron.
  2. An atom becoming charged when it loses a proton.
  3. An atom becoming charged when it loses a neutron.
  4. An atom becoming charged when it loses an isotope.

Correct Answer:

  1. An atom becoming charged when it loses an electron.

Q23. Polonium-209 decays to form Lead-205. What type of radiation has been released?

Options:

  1. Alpha
  2. Beta
  3. Gamma
  4. Neutron

Correct Answer:

  1. Alpha

Q24. What is meant by 'background radiation'?

Options:

  1. The amount of radiation that comes from man-made sources we are constantly exposed to.
  2. The radiation left-over from nuclear accidents.
  3. The radiation we are exposed to from space.
  4. The normal radiation we are exposed to from natural and man-made sources.

Correct Answer:

  1. The normal radiation we are exposed to from natural and man-made sources.

Q25. Which type of radiation is most suitable to use within a smoke detector?

Options:

  1. Alpha
  2. Beta
  3. Gamma
  4. Neutron

Correct Answer:

  1. Alpha

Q26. Which type of radiation is most suitable to use in paper production?

Options:

  1. Alpha
  2. Beta
  3. Gamma
  4. Neutron

Correct Answer:

  1. Beta