Question 1025890
 The half-life of radium is approximately 1600 years.
 If the present amount of radium in a certain location is 700 grams, how much will remain after 1200 years?
 Express your answer to the nearest gram
:
the formula we will use here: A = Ao*2(-t/h), where
A = remaining amt after t time
Ao = initial amt
h = half-life of substance
t = time of decay 
In this problem
A = 700*2(-1200/1600)
reduce the fraction
A = 700*2(-3/4)
using a calc
A = 700 * .5946
A = 416 grams