Question

The half-life for a 100-gram sample of radioactive element X is 5 days. How much of element X remains after 10 days have passed?

A.
75 g

B.
50 g

C.
100 g

D.
25 g

Answer 1

25g

Step-by-step explanation:

Given parameters:

Half life of X = 5days

Mass of sample of radioactive elements = 100g

The half-life of a radioactive material is the time it takes for a sample to decay by half. At the half-life, an original sample would have yielded equal daughter to parent ratio.

At time (days) Mass of sample

0 100g

5 50g

10 25g

Every 5 days, the sample will split into half.

Therefore, 25g will remain after 10days.