7bRadioactivity

Syllabus objectives

• 7.2describe the structure of an atom in terms of protons, neutrons and electrons and use symbols such as 6 C to describe particular nuclei
• 7.3know the terms atomic (proton) number, mass (nucleon) number and isotope
• 7.4know that alpha (α) particles, beta (β−) particles, and gamma (γ) rays are ionising radiations emitted from unstable nuclei in a random process
• 7.5describe the nature of alpha (α) particles, beta (β−) particles and gamma (γ) rays, and recall that they may be distinguished in terms of penetrating power and ability to ionise
• 7.6practical: investigate the penetration powers of different types of radiation using either radioactive sources or simulationsPractical
• 7.7describe the effects on the atomic and mass numbers of a nucleus of the emission of each of the four main types of radiation (alpha, beta, gamma and neutron radiation)
• 7.8understand how to balance nuclear equations in terms of mass and charge
• 7.9know that photographic film or a Geiger−Müller detector can detect ionising radiations
• 7.10explain the sources of background (ionising) radiation from Earth and space
• 7.11know that the activity of a radioactive source decreases over a period of time and is measured in becquerels
• 7.12know the definition of the term 'half-life' and understand that it is different for different radioactive isotopes
• 7.13use the concept of the half-life to carry out simple calculations on activity, including graphical methods
• 7.14describe uses of radioactivity in industry and medicine
• 7.15describe the difference between contamination and irradiation
• 7.16describe the dangers of ionising radiations, including: • that radiation can cause mutations in living organisms • that radiation can damage cells and tissue • the problems arising from the disposal of radioactive waste and how the associated risks can be reduced