A certain radioactive element has a half-life of one hour. If you start with 40.0 grams of the element at noon, how much of the radioactive element will be left at 2 p.m.?

Question

ganeshie8 · Answer

element has half-life of 1 hour means, it becomes half in 1 hour.

ganeshie8 · Answer

40 grams becomes half in one hour, which means it becomes 20 grams

ganeshie8 · Answer

just after that,
20 grams becomes half in another one hour, which means it becomes 10 grams

so... 40 grams reduces to 10 grams in 2 hours

ganeshie8 · Answer

does that make sense ?

anonymous · Answer

10 is wrong

anonymous · Answer

No... I got it correct!!  Maybe you had a slightly different problem @joselynnr because I specifically got 3 points for it