How can half-life be described in terms of radioactive decay?

1 Answer

It is the time taken for the intensity of the radioactive emission to decay to half of its original intensity.

Explanation:

This is by definition.
Most radioactive decay follows the natural logarithmic law, ie

#I(t)=I_0e^(-lamdat#

Lamda is a constant which differs for different radioactive materials and that is why each on has a different half life.
So the half life is the time taken for I to reach exactly half of #I_0#, ie

#t=t_(1/2)iffI=1/2I_0#