Question 22M.1A.SL.TZ2.27
| Date | May 2022 | Marks available | [Maximum mark: 1] | Reference code | 22M.1A.SL.TZ2.27 |
| Level | SL | Paper | 1A | Time zone | TZ2 |
| Command term | Question number | 27 | Adapted from | N/A |
What statement is not true about radioactive decay?
A. The percentage of radioactive nuclei of an isotope in a sample of that isotope after 7 half-lives is smaller than 1 %.
B. The half-life of a radioactive isotope is the time taken for half the nuclei in a sample of that isotope to decay.
C. The whole-life of a radioactive isotope is the time taken for all the nuclei in a sample of that isotope to decay.
D. The half-life of radioactive isotopes range between extremely short intervals to thousands of millions of years.
[1]
C
There was some questioning about the use of the term 'whole-life' from teacher comments. As that option (C) was the correct answer and the most popular it did not confuse the candidates. The statement is clearly incorrect and the use of a non physics specific term that might be used in a general discussion was felt to be acceptable.
