Environmental Science
Intermediate

Radioactive Decay

Amount remaining after a number of half-lives.

Formula

N=N0(12)t/t1/2N = N_0\left(\frac{1}{2}\right)^{t/t_{1/2}}

Variables

N_0Initial amount
tElapsed time
t_{1/2}Half-life

Example

After 2 half-lives, 25% remains

Did You Know?

Carbon-14 dating relies on its 5730-year half-life.

nucleardecay