Respuesta :
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.
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.