Radioactivity & Particles
under construction
The various syllabus statements cover very different quantities of material. I'm sorry there aren't any pictures yet. You need to read this page in conjunction with block 7 of the syllabus specification. xxx represents a page number in England, (3rd edition).
Relevant to quite a lot of this section is the page on nuclear reactions.
| 1 |
use the following units: becquerel (Bq), centimetre (cm), hour (h), minute (min), second (s) 312-325 |
| 2 |
describe the structure of an atom in terms of protons, neutrons and electrons and use symbols such as 146C to describe particular nuclei31 2-313 |
| 3 | understand the terms atomic (proton) number, mass (nucleon) number and isotope 314-315 |
| 4 |
understand that alpha and beta particles and gamma rays are ionising radiations emitted from unstable nuclei in a random process |
| 5 |
describe the nature of alpha and beta particles and gamma rays and recall that they may be distinguished in terms of penetrating power 316-317 |
| 6 |
describe the effects on the atomic and mass numbers of a nucleus of the emission of each of the three main types of radiation 314-315 |
| 7 | understand how to complete balanced nuclear equations 314-315 |
| 8 |
understand that ionising radiations can be detected using a photographic film or a Geiger-Muller detector 316-317 |
| 9 | recall the sources of background radiation 315, 324 |
| 10 |
understand that the activity of a radioactive source decreases over a period of time and is measured in becquerels 318-319 |
| 11 |
recall the term ‘half-life’ and understand that it is different for different radioactive isotopes 318-319 |
| 12 | use the concept of half-life to carry out simple calculations on activity 318-319 |
| 13 |
describe the uses of radioactivity in medical and non-medical tracers, in radiotherapy and in the radioactive dating of archaeological specimens and rocks 328-329 |
| 14 |
describe the dangers of ionising radiations, including
radiation can damage cells and tissue 324-325 |
| 15 |
describe the results of Geiger and Marsden’s experiments with gold foil and alpha particles 320 |
| 16 |
describe Rutherford’s nuclear model of the atom and how it accounts for the results of Geiger and Marsden’s experiment and understand the factors (charge and speed) which affect the deflection of alpha particles by a nucleus 320 |
| 17 |
understand that a nucleus of U-235 can be split (the process of fission) by collision with a neutron, and that this process releases energy in the form of kinetic energy of the fission products 322-323 |
| 18 |
recall that the fission of U-235 produces two daughter nuclei and a small number of neutrons 322-323 |
| 19 |
understand that a chain reaction can be set up if the neutrons produced by one fission strike other U-235 nuclei 322-323 |
| 20 |
understand the role played by the control rods and moderator when the fission process is used as an energy source to generate electricity 322-323 |
Avoid the use of the word 'strong' in relation to radioactive decay. It is ambiguous, and you need to distinguish between
High count rate (or activity), which means that lots of particles are given off each second. If each particle is relatively harmless a high count rate might not be very serious.
Highly ionising, which means that each particle can do a lot of damage.
High penetration, which probably means that each particle doesn't do all that much damage, because the damage is only done when a particle stops, thereby delivering its energy to the object that stopped it.