4.4.2.3 Half-lives and the Random Nature of Radioactive Decay

Question 1

Is radioactive decay regular?

Answer 1

random - variations are more pronounced at low count rates - background radiation

Question 2

Half-life:

Answer 2

half-life of a radioactive isotope is the time it takes for the number of nuclei of the isotope to halve

OR

the time is takes for the count rate (or activity) from a sample containing the isotope to fall to half its initial level

Question 3

Why is substance having short half-life good?

Answer 3

• activity decreases quickly
• risk of harm decreases quickly