Solutions

Final test: Edexcel Additional Radioactivity P2.5 P2.6 (15 marks)

  1. If a radioactive isotope emits an alpha particle, what changes to the nucleus of the atom will result? (circle the correct answer).
  1. The atomic number will reduce by two and the mass will reduce by four.
  2. The atomic mass will reduce by two and an electron will be lost.
  3. The atomic number will increase by one and the mass will stay the same.
  4. The atomic mass will reduce by two and the atomic number stays the same.

(1 mark)

  1. Tick one box in each column to show which type of material can be used to shield (stop) the type of radiation described.

Type of radiation / Only stopped by lead or a few metres of concrete / Penetrates paper but stopped by a sheet of Aluminium / Stopped by a sheet of paper
Gamma / 
Alpha / 
Beta / 

(1 mark)

  1. A radioactive isotope has a count rate of 504Bq. After 27 days this has fallen to 63Bq.

Use this information to calculate the half life of the isotope.

540242 12663

1 half-life 1 half-life 1 half life

Reduced by 3 half-lives in 27 days

27 = 9

3

Half-life of isotope = 9 days

(4 marks)

  1. The table below gives some information about radioactive isotopes. Using this information, say which isotope would be most suitable to be used as a medical tracer in the body and explain your choice.

  • Sodium 24
  • Short half life
  • But long enough to complete medical tests
  • Short half-life results in less radiation risk

(3 marks)

  1. QWC: Describe the main differences between nuclearfission and nuclear fusion.

QWC Suggested marking guidance (Total 6 marks)
Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. Teachers should and apply a ‘best-fit’ approach to the marking.
0 marks / Level 1 (1-2 marks) / Level 2 (3-4 marks) / Level 3 (5-6 marks)
No relevant content. / Attempt at a description 1-2 marking points.
The spelling, punctuation and grammar are very weak. / Brief description 3-4 marking points.
There is reasonable accuracy in spelling, punctuation and grammar, although there may still be some errors / Clear description almost all marking points.
The answer shows almost faultless spelling, punctuation and grammar.

Fission

  • A single atom
  • Disintegrating and releasing energy
  • To produce two or more new elements

Fusion

  • More than one atom
  • Joining together to release energy
  • And producing a new, larger atom

(6 marks)

1

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