Question

Element X decays radioactively with a half life of 6 minutes. If there are 260 grams of Element X, how long, to the nearest tenth of a minute, would it take the element to decay to 113 grams

Answer 1

7.2 minutes

Explanation:

The formula to find the time using the radioactive decay rate formula is given as:

t = t½ × In(Nt/No)/-In2

Where

t½ = half life = 6 minutes

No = Initial Amount = 260 grams

Nt = Amount after decay

= 113 grams

Hence:

t = 6 × In(113/260)/-In2

t = 7.2131331036796 minutes

Approximately = 7.2 minutes