Answer:
Amount left after 25 days = 12.5 g
Explanation:
Given data:
Mass of sample = 400 g
Half life of sample = 5 days
Mass left after 25 days = ?
Solution:
First of all we will calculate the number of half lives passes in given time period.
Number of half lives = Time elapsed / Half life
Number of half lives = 25 days/ 5 days
Number of half lives = 5
At time zero = 400 g
At 1st half life = 400 g/2 = 200 g
At 2nd half life = 200 g/2 = 100 g
At 3rd half life = 100 g/2 = 50 g
At 4th half life = 50 g/2 = 25 g
At 5th half life = 25 g/2 = 12.5 g
