When a radioactive isotope is set up close to a radiation detector, a count rate of 80,000 counts/s80,000\text{ counts/s}80,000 counts/s is initially obtained. The table shows the count rate from the isotope over a three-day period:
| Time (days) | Count rate (counts/s) |
|---|---|
| 0 | 80,000 |
| 1 | 61,000 |
| 2 | 46,000 |
| 3 | 35,000 |
What is the half-life of the isotope?
less than 1 day
more than 1 day but less than 2 days
more than 2 days but less than 3 days
more than 3 days
144 exam-style questions on CIE IGCSE Physics 5.2.4a Half-life. Each one has a worked solution and a mark scheme showing where the marks go.