Radioactive substance A breaks down to substance B with a half-life of 1,000 years.If we start out with four kilograms of radioactive substance A,how much of those four kilograms of substance A will remain in 3,000 years?
A)250 grams
B)500 grams
C)1 kilogram
D)2 kilograms

Question

Quizplus · Accepted Answer

After 1,000 years, half of the substance A will have decayed into substance B, leaving 2 kilograms of substance A. After another 1,000 years (2,000 years total), half of the remaining 2 kilograms will have decayed into substance B, leaving 1 kilogram of substance A. After another 1,000 years (3,000 years total), half of the remaining 1 kilogram will have decayed into substance B, leaving 0.5 kilograms or 500 grams of substance A.

Radioactive Substance a Breaks Down to Substance B with a Half-Life