Question

A sample contains 10 g of a radioactive isotope. How much radioactive isotope will remain in the sample after 1 half-life?

a.5.0
b. 2.5
c. 7.5
d.10

Answer 1

5.0

Step-by-step explanation:

just took the test

Answer 2

After one half-life, 50% of the sample has decayed and
is no longer radioactive.

50% of the original 10 g is 5 g.

After one half-life, 5 g has decayed, and 5 g remains. (a)