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

1 Answer
Aug 5, 2017

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