Question

If a radioactive substance starts at 100 grams and decays to 12.5 grams in 21.6 hours, what is the substance's half-life?
A. 3 hours
B. 7.2 hours
C. 14.4 hours
D. 21.6 hours

Answer 1

Hello,

Your brainliest answer would be:

10.2

But I don’t not see a choice like that

So let’s go with the closest

B. 7.2 hours

Plz mark me brainliest!

Hope this helps!