Complete the missing entries (i) to (iv) in the table showing the properties of different types of radiation:
| Type of radiation | Number of protons | Number of neutrons | Charge / C\text{C}C | Stopped by |
|---|---|---|---|---|
| α\alphaα | 2 | (i) | +3.2×10−19+3.2 \times 10^{-19}+3.2×10−19 | thin sheet of paper |
| β\betaβ | (ii) | 0 | (iii) | thin sheet of aluminium |
| γ\gammaγ | 0 | 0 | 0 | (iv) |
State how β\betaβ-decay changes the nucleus of an atom.
A radiation detector used in a laboratory detects a background count rate of 35 counts/min35\text{ counts/min}35 counts/min. A radioactive source is placed in front of the radiation detector. The initial reading on the detector is 835 counts/min835\text{ counts/min}835 counts/min. The half-life of the source is 20 minutes20\text{ minutes}20 minutes.
Calculate the expected reading on the detector after 80 minutes80\text{ minutes}80 minutes.
State two safety precautions taken when moving, using, or storing radioactive sources in a laboratory.
484 exam-style questions on CIE IGCSE Physics 5.2 Radioactivity, covering 5.2.1 Background radiation and measuring count rate, 5.2.2a Alpha, beta and gamma emission, 5.2.2b Deflection and ionising effects of nuclear radiation, 5.2.3a Radioactive decay, 5.2.3b Effects of decay on the nucleus and decay equations, 5.2.4a Half-life, 5.2.4b Choosing isotopes for applications, and 5.2.5 Effects of ionising radiation and safety precautions. Each one has a worked solution and a mark scheme showing where the marks go.