A nucleus of oxygen-15 has the nuclide notation: 815O{}^{15}_{8}\text{O}815O.
Determine:
(i) the number of protons in one nucleus of oxygen-15.
(ii) the number of neutrons in one nucleus of oxygen-15.
(iii) the number of electrons in one neutral atom of oxygen-15.
A detector measures the radioactivity of a sample of oxygen-15.
The table below shows the record of count rates measured at regular intervals of 1 minute.
| Time (min\text{min}min) | Count rate (counts/s\text{counts/s}counts/s) |
|---|---|
| 0 | 400 |
| 1 | 283 |
| 2 | 200 |
| 3 | 141 |
| 4 | 100 |
| 5 | 71 |
| 6 | 50 |
Calculate the half-life of oxygen-15 using information from the table.
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.