Below, draw a diagram of an apparatus that could be used to demonstrate that the source emits alpha-particles.
Describe the way this apparatus is used.
Explain how the test results show that the source emits alpha-particles.
Compare the relative ionising abilities and penetrating powers of alpha-particles, beta-particles and gamma rays.
Radium-224 is another source that emits alpha-particles. It has a half-life of 3.6 days. Explain why americium-241 is more suitable as the radioactive source in a smoke detector than radium-224.
A smoke detector contains $8.0 \times 10^{11}$ atoms of americium-241. Calculate the length of time for the number of americium-241 atoms to decrease to $1.0 \times 10^{11}$.
State one harmful consequence of background radiation.
A radioactive source is lifted with a long-handled tool. Explain why this is safer than using a short-handled tool.