Question

The half-life of a radioactive kind of protactinium is one minute. If you start with 88 g of it, how much will be left over after two minutes?

Answer 1

This is my workings

Answer 2

Answer:

22 grams

Step-by-step explanation:

Divide the number of minutes by the half life...    2/1=2

Multiply starting amount by one-half (1/2) a total of the number of half-lives that have passed. ( 2 half lives in our case)

88 * 1/2 *1/2 = 22 grams     also written as 88(1/2)^2