You can find the half life from the graph. Get the initial activity (t=0), half it, draw a horizontal line from there to the graph, draw a vertical line from the graph to the time axis, read off the half life and double check your units.

Half life = Ln2/Decay constant T(1/2)=Ln2/λ

To find out how many atoms left: N=N0e^(-λt)

N0 = Start no. of atoms, λ = decay constant and t = time (in seconds)

N=N0e^(-λt) is the most important equation in radioactivity... don't forget it... say it over and over... N=N0e^(-λt)... N=N0e^(-λt)...

...N=N0e^(-λt) ...N=N0e^(-λt) ...N=N0e^(-λt)...

## Comments

No comments have yet been made