Question

a sample with a half life of 22.5 hours had a mass of 0.035 grams after it has decayed 180 hours. what was its mass to begin with?

Answer 1

Explanation:

The sample will lose half of its mass after 4 hours. The half life.

# 8/2 = 4#

The sample will lose half of the remaining four after another half life.

# 4/2 = 2 #