Question

A radioactive sample has a half life of 1500 years. A sealed tube containing 1g of the sample will contain after 3000years.

(A) 1 g of the sample
(B) 0.5 g of the sample
(C) 0.25 g of the sample
(D) 0.00 g of the sample

Answer 1

a half life means how long it takes to get to half of the material. So after one half-life, the sample will have 1/2 grams of sample, and after 2 half-lives there will be 1/4 of the sample, or 0.25g.

Answer 2

The answer is c. 0.25 because it starts at 1, then after 1500 years it's a .5 and then at another 1500 it's .25. It's called a half life because it'll be in half after the time period ends.