AQA-style topic test · Atomic Structure · Foundation tier
Time allowed: 35 minutes
Total: Separate Physics 30 marks · Combined Science 24 marks (skip Question 06)
You need: a calculator and a ruler.
Instructions: Answer all questions on paper. Show your working in calculations. Open the mark schemes only when you have finished the whole test.
Question 01
01.1 Which particle in an atom has no charge?
Tick (✓) one box.
☐ electron ☐ neutron ☐ proton [1 mark]
Mark scheme
neutron (1)
01.2 What is the approximate radius of an atom?
Tick (✓) one box.
☐ 1 × 10−2 m ☐ 1 × 10−6 m ☐ 1 × 10−10 m ☐ 1 × 10−14 m [1 mark]
Mark scheme
1 × 10−10 m (1)
01.3 What are isotopes? [1 mark]
Mark scheme
atoms of the same element (same number of protons) with different numbers of neutrons (1)
01.4 An atom of carbon-14 has an atomic number of 6 and a mass number of 14.
How many neutrons and how many electrons does it have? [2 marks]
Mark scheme
neutrons: 14 − 6 = 8 (1)
electrons: 6 (1)
Question 01 total: 5 marks
Question 02
Scientists’ model of the atom has changed over time.
02.1 Describe the plum pudding model of the atom. [1 mark]
Mark scheme
a ball of positive charge with negative electrons embedded in it (1)
In the alpha particle scattering experiment, alpha particles were fired at thin gold foil.
02.2 Most alpha particles went straight through the foil. What did this show? [1 mark]
Mark scheme
most of the atom is empty space (1)
02.3 A few alpha particles bounced back. What did this show? [1 mark]
Mark scheme
the mass and positive charge are concentrated in a tiny nucleus at the centre (1)
02.4 Which scientist showed that the nucleus contains neutrons?
Tick (✓) one box.
☐ Bohr ☐ Chadwick ☐ Rutherford ☐ Thomson [1 mark]
Mark scheme
Chadwick (1)
02.5 Why do scientific models change over time? [1 mark]
Mark scheme
new experimental evidence is found that the old model cannot explain (1)
Question 02 total: 5 marks
Question 03
03.1 Complete the table to show what stops each type of radiation. Choose from: a few cm of air or a sheet of paper · a few mm of aluminium · several cm of lead. [3 marks]
| Radiation | Stopped by |
|---|---|
| alpha | _______________ |
| beta | _______________ |
| gamma | _______________ (greatly reduced) |
Mark scheme
alpha: a sheet of paper / a few cm of air (1)
beta: a few mm of aluminium (1)
gamma: several cm of lead (1)
03.2 Which type of radiation is the most ionising? [1 mark]
Mark scheme
alpha (1)
03.3 What is a beta particle? [1 mark]
Mark scheme
a high-speed electron (emitted from the nucleus) (1)
Question 03 total: 5 marks
Question 04
Table 1 shows how the count-rate from a radioactive source changes with time.
| Time (hours) | 0 | 5 | 10 | 15 |
|---|---|---|---|---|
| Count-rate (counts per minute) | 800 | 400 | 200 | 100 |
04.1 What is meant by half-life? [1 mark]
Mark scheme
the time it takes for the number of unstable nuclei in a sample (or the count-rate) to halve (1)
04.2 Use Table 1 to find the half-life of the source. [1 mark]
Mark scheme
5 hours (1)
04.3 Predict the count-rate after 20 hours. [1 mark]
Mark scheme
50 counts per minute (1)
04.4 Radioactive decay is random. What does this mean? [1 mark]
Mark scheme
you cannot predict which nucleus will decay next / when a particular nucleus will decay (1)
04.5 Radium-226 decays by alpha emission. Complete the nuclear equation.
22688Ra → ??Rn + 42He [2 marks]
Mark scheme
mass number 222 (1)
atomic number 86 (1)
Question 04 total: 6 marks
Question 05
05.1 What is the difference between radioactive contamination and irradiation? [2 marks]
Mark scheme
contamination: unwanted radioactive atoms get onto or into an object (1)
irradiation: an object is exposed to radiation but does not become radioactive (1)
05.2 Give one way a teacher reduces the risk when using a radioactive source. [1 mark]
Mark scheme
any one from (1): handle with tongs · keep the source at arm’s length · point it away from people · limit the time it is out · store it in a lead-lined box
Question 05 total: 3 marks
🔷 SEPARATE PHYSICS ONLY – Combined Science students skip Question 06
(Background radiation, uses of radiation, and nuclear fission and fusion are only in Separate Physics.)
Question 06
06.1 Give one natural source and one man-made source of background radiation. [2 marks]
Mark scheme
natural: rocks (e.g. radon gas) / cosmic rays from space (1)
man-made: fallout from nuclear weapons testing / nuclear accidents / medical X-rays (1)
06.2 Describe what happens in nuclear fission. [2 marks]
Mark scheme
a large, unstable nucleus (e.g. uranium) absorbs a neutron (1)
and splits into two smaller nuclei, releasing energy and two or three neutrons (1)
06.3 What is nuclear fusion? [1 mark]
Mark scheme
the joining of two light nuclei to form a heavier nucleus (releasing energy) (1)
06.4 A radioactive tracer is injected into a patient. Why should it have a short half-life? [1 mark]
Mark scheme
so it does not stay radioactive in the body for long / to reduce the patient’s dose (1)
Question 06 total: 6 marks
END OF TEST. Total: Separate Physics 30 marks · Combined Science 24 marks.
Next: Atomic Structure – Higher test · Atomic Structure topic page · All topic tests
