Question

The half-life of tritium (h) is 12 years. How long does it take for 16. 0 ng of tritium to decay to the point where 2. 0 ng remains?

Answer 1

36 years

Step-by-step explanation:

2 = 16 * (1/2)^n where n is the number of half lives

2/16 = (1/2)^n

1/8 = (1/2)^n

log (1/8) = log (1/2^n)

log(1/8) = n log (1/2)

log ( 1/8 ) / log(1/2) = n = 3 half lives

each half life is 12 years so 3 * 12 = 36 years