The equationthat is usedfor radioactivedecayis We wantto find an expressionfor the half-life
of an isotope.Sincehalf-lifeis definedas the time it takesfor a sampleto lose half of its nuclei,then if we
startingwith an initialmass (measuredin grams),then after sometime will becomehalf the amount
that we startedwith, Substitutingthis into the exponentialdecaymodel,
Canceling from both sides,
Solvingfor whichis the half-life,by takingthe naturallogarithmon both sides,
Solvingfor and denotingit with new notation for half-life(a standardnotationin physics),