(a)[1]
Describe what is meant by the term ‘spontaneous’ emission.
(b)[2]
Describe what an alpha particle is composed of.
(c(i))[3]
Describe the arrangement of either a cloud chamber or a spark counter. Your answer must include a labelled drawing of the apparatus.
(c(ii))[1]
Describe how randomness in alpha-particle emission is shown by the apparatus you described in (c)(i).
(c(iii))[2]
A radioactive source gives 120 tracks in one minute in a cloud chamber. 6.0 hours later, the same source gives 15 tracks in one minute. When the source is absent, no tracks are seen. Calculate the half-life of the radioactive isotope in the source.