A certain element has a half-life of 120 years. After a certain sample of that element was stored for 600 years, only 2 grams was left. How many grams were in the original sample?

2 == E x 1/2^(600/120)

2 ==E x 1/2^(5)

2 ==E x 0.03125

E ==2 / 0.03125

E == 64 grams - amount of original element.