what is the equation to find a half life?

Half-life

$$The radioactive decay equation is $N = N_0e^{-\lambda t}$ where $N$ is number of particles at time $t$, $N_0$ is the number of particles at time zero, and $\lambda$ is the decay constant. The half-life, $t_\frac{1}{2}$ is the time taken to get from $N_0$ to $\frac{1}{2}N_0$ and is related to the decay constant by$$ t_\frac{1}{2}=\frac{ln(2)}{\lambda}$$

2/x

(just to let you know, x=the full life)

Hi Jeyden,

x/2 is half of x.  (Yours is upside down)