Answer:
6.25%
Explanation:
Given data:
Total sample = 150 g
Percentage remain after 4 half life = ?
Solution:
at time zero 150 g
At first half life = 150 g/2 = 75 g
At 2nd half life = 75 g/ 2 = 37.5 g
At 3rd half life = 37.5 g/2 = 18.75 g
At 3rd half life = 18.75 g/2 = 9.375 g
Percentage remain after 4 half lives.
9.375 g / 150 g × 100
0.0625 × 100
6.25%
