Ah, yes
if you start with P amount of something and the half life is h units (in years) and the time elapsed is t (in years) then the amount left is A
the equation is
so
given
h=1620
P=150
t=200
so
use your calculator
A≈137.69781917515g
about 138grams left
if you start with P amount of something and the half life is h units (in years) and the time elapsed is t (in years) then the amount left is A
the equation is
so
given
h=1620
P=150
t=200
so
use your calculator
A≈137.69781917515g
about 138grams left