The graph shows how the number of atoms of a radioactive isotope in a sample varies with time.
Activity is the rate at which a source of unstable nuclei decays. Determine the activity of the radioactive sample at 200 seconds. Give the unit.
Practise AQA GCSE Physics Atoms and nuclear radiation with exam-style questions for Foundation and Higher tier. 21 questions covering Radioactive decay and nuclear radiation, Nuclear equations, Half-lives and the random nature of radioactive decay, and Radioactive contamination, matched to the AQA GCSE Physics (8463) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.