The half-life of a chemical species is the time it takes for its concentration to fall to half of the initial value. Assume the half life is two years and the decay begins in 1980:
- 1980 – 100%
- 1982 – 50%
- 1984 – 25%
- 1986 – 12.5%
- 1988 – 6.25%
- and so on…
Rob Sterling 