GCSE Combined Science Atomic structure and radioactivity questions by topic

This question is about the structure of the atom.

1. (a)Name the two particles found in the nucleus.[1]
2. (b)State what the atomic number Z tells you.[1]
3. (c)State what the mass number A tells you.[1]
4. (d)State the charge on an electron.[1]

Chlorine has two isotopes, ³⁵₁₇Cl and ³⁷₁₇Cl.

1. (a)State what is meant by an isotope.[1]
2. (b)State how the two chlorine isotopes differ.[1]
3. (c)Calculate the number of neutrons in ³⁷₁₇Cl.[1]
4. (d)Explain why both isotopes react identically in chemical reactions.[1]

This question is about the three nuclear radiations.

1. (a)Describe the composition of an alpha particle.[1]
2. (b)State what a beta-minus particle is.[1]
3. (c)State what sort of wave a gamma ray is.[1]
4. (d)Name the radiation stopped by a single sheet of paper.[1]

480 Bq is the starting activity of a source whose half-life is 5.0 days.

1. (a)State what is meant by half-life.[2]
2. (b)Calculate the activity after 10 days.[1]
3. (c)State the fraction of the original activity that remains after 10 days.[1]

This question is about how the atomic model developed.

1. (a)Describe the plum pudding model of the atom.[1]
2. (b)Alpha particles were fired at thin gold foil. State what most of them did, and what the few that bounced straight back proved.[3]
3. (c)Name the scientist who discovered the neutron.[1]

This question is about balancing decay equations.

1. (a)State the two quantities that must balance on both sides of a nuclear equation.[2]
2. (b)Radon-222 (²²²₈₆Rn) decays by alpha emission. State the mass number and atomic number of the daughter nucleus.[2]
3. (c)Explain why the daughter is a different element from radon.[1]

A source's count rate is 800 s⁻¹. After 4.0 hours it reads 400 s⁻¹, and after 8.0 hours it reads 200 s⁻¹.

1. (a)Determine the half-life of the source.[2]
2. (b)Calculate the count rate after 12 hours.[2]
3. (c)Explain why the count rate never falls exactly to zero.[1]

This question is about choosing radioactive sources for different jobs.

1. (a)Explain why medical tracers use gamma emitters with short half-lives.[2]
2. (b)Explain why an alpha emitter is useless as a tracer detected outside the body.[1]
3. (c)Explain why gamma is suited to sterilising sealed single-use instruments.[2]

Uranium-238 (²³⁸₉₂U) decays by alpha emission.

1. (a)State the mass number and atomic number of the daughter nucleus.[2]
2. (b)Write the nuclear equation for this decay.[2]
3. (c)The daughter then undergoes two further alpha decays. State the A and Z values of the final nucleus.[1]

Strontium-90 (⁹⁰₃₈Sr) is a beta-minus emitter.

1. (a)State the mass number and atomic number of the daughter nucleus.[2]
2. (b)Explain what changes inside the nucleus during this decay.[2]
3. (c)State whether the emitted electron was orbiting the atom before the decay. Give a reason.[1]
4. (d)State what happens to the mass number during beta-minus decay.[1]

A wooden artefact contains 25% of the carbon-14 expected in living wood. Carbon-14 has a half-life of 5 700 years.

1. (a)State how many half-lives have passed.[1]
2. (b)Calculate the age of the artefact.[2]
3. (c)State one assumption radiocarbon dating makes.[1]
4. (d)Explain why carbon-14 suits the dating of once-living material.[1]

A detector beside a source reads 76 s⁻¹. With the source removed, it reads 12 s⁻¹.

1. (a)Explain why the two readings differ and calculate the corrected count rate.[2]
2. (b)The source's half-life is 20 minutes. Calculate the corrected count rate after 60 minutes.[2]
3. (c)Calculate the total reading the detector would show after 60 minutes.[1]
4. (d)State one natural source of the background radiation in the 12 s⁻¹ reading.[1]