7 Radioactivity and particles
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Radioactivity and particles units
7.1
Use the following units: becquerel (Bq), centimetre (cm), hour (h), minute (min) and second (s)
(b) Radioactivity
7.2Atomic structure and nuclei
Describe atomic structure using protons, neutrons and electrons, and use nuclide notation such as ¹²₆C for particular nuclei.
7.3Atomic number, mass number and isotopes
Know the terms atomic (proton) number, mass (nucleon) number and isotope
7.4Ionising radiation
Know that alpha (α) particles, beta (β-) particles, and gamma (γ) rays are ionising radiations emitted from unstable nuclei in a random process
7.5Alpha, beta and gamma radiation
Describe alpha (α) particles, beta (β⁻) particles and gamma (γ) rays and distinguish them by penetrating power and ionising ability.
7.6Radiation penetration practical
Practical: investigate the penetration powers of different types of radiation using either radioactive sources or simulations
7.7Nuclear emission effects
Describe 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)
7.8Balancing nuclear equations
Understand how to balance nuclear equations in terms of mass and charge
7.9Detecting ionising radiation
Know that photographic film or a Geiger-Müller detector can detect ionising radiations
7.10Background radiation
Explain the sources of background (ionising) radiation from Earth and space
7.11Radioactive activity
Know that the activity of a radioactive source decreases over a period of time and is measured in becquerels
7.12Half-life
Know the definition of the term 'half-life' and understand that it is different for different radioactive isotopes
7.13Half-life calculations
Use the concept of the half-life to carry out simple calculations on activity, including graphical methods
7.14Uses of radioactivity
Describe uses of radioactivity in industry and medicine
7.15Contamination and irradiation
Describe the difference between contamination and irradiation
7.16Dangers of ionising radiation
Describe 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
(c) Fission and fusion
7.17Nuclear reactions as energy sources
Know that nuclear reactions, including fission, fusion and radioactive decay, can be a source of energy
7.18Nuclear fission
Understand how a nucleus of U-235 can be split (the process of fission) by collision with a neutron and that this process releases energy as kinetic energy of the fission products
7.19Fission products
Know that the fission of U-235 produces two radioactive daughter nuclei and a small number of neutrons
7.20Chain reactions
Describe how a chain reaction can be set up if the neutrons produced by one fission strike other U-235 nuclei
7.21Control rods and moderator
Describe the role played by the control rods and moderator in the fission process
7.22Reactor shielding
Understand the role of shielding around a nuclear reactor
7.23Fusion and fission
Explain the difference between nuclear fusion and nuclear fission
7.24Nuclear fusion
Describe nuclear fusion as the creation of larger nuclei resulting in a loss of mass from smaller nuclei, accompanied by a release of energy
7.25Fusion in stars
Know that fusion is the energy source for stars
7.26Fusion conditions
Explain why nuclear fusion does not happen at low temperatures and pressures, due to electrostatic repulsion of protons