P2 - Half Life Flashcards
1
Q
What happens to radioactivity as a sample becomes older and why?
A
It decreases because the unstable nuclei have almost all disappeared.
2
Q
Why is it difficult to measure activity of a radioactive sample?
A
It never reaches 0.
3
Q
What is half-life?
A
The average time it takes for the number of nuclei in a radioactive sample to halve.
4
Q
What does each decay of a nuclear atom mean?
A
One more radioactive nucleus has disappeared.
