Question

Carbon-14 has a half-life of 5730 years. How much of a 144 g sample of carbon-14 will remain after 1719 years?

Answer 1

The mass remaining is `=117g`

Explanation:

The half life of carbon-`14` is `t_(1/2)=5730y`

This means that in `5730y`, the initial amount of carbon`-14` will be halved

The radioactive constant is

`lambda=ln2/t_(1/2)=ln2/5730=0.000121`

The fundamental decay equation is

`m=m_0e^(-lambdat)`

The initial amount of carbon`-14` is `m_0=144g`

The time is `t=1719y`

Therefore

`m=144*e^(-0.000121*1719)=144*e^-0.208=117g`