Question

The half-life of a certain material is 0.002 second. Approximately how much of a 14-gram sample will be left after 0.004 second?

A.
12 grams
B.
3.5 grams
C.
0.06 gram
D.
7 grams

Answer 1

B. 3.5 grams.

Explanation:

After 0.002 seconds 1/2 * 14 = 7 grams will be left.

After another 0.002 seconds ( total 0.004 seconds), 1/2 * 7 = 3.5 grams will be left.