P2.5 - AQA GCSE Physics Unit 2 - Overview




What happens when radioactive substances decay, and the uses and dangers of their emissions

Radioactive substances emit radiation from the nuclei of their atoms all the time. These nuclear radiations can be very useful but may also be very dangerous. It is important to understand the properties of different types of nuclear radiation.

To understand what happens to radioactive substances when they decay we need to understand the structure of the atoms from which they are made. The use of radioactive sources depends on their penetrating power and half-life.

Candidates should use their skills, knowledge and understanding to:

■ evaluate the effect of occupation and/or location on the level of background radiation and radiation dose
■ evaluate the possible hazards associated with the use of different types of nuclear radiation
■ evaluate measures that can be taken to reduce exposure to nuclear radiations
■ evaluate the appropriateness of radioactive sources for particular uses, including as tracers, in terms of the type(s) of radiation emitted and their half-lives
■ explain how results from the Rutherford and Marsden scattering experiments led to the 'plum pudding' model being replaced by the nuclear model.

Candidates should realise that new evidence can cause a theory to be re-evaluated.

Candidates should realise that, according to the nuclear model, most of the atom is empty space.

This section of the second unit is broken into two sections:

P2.5.1 - Atomic structure

P2.5.2 - Atoms and radiation

There is also a page suggesting practical experiments that should be carried out during the study of this section.