Answer:
True
Explanation:
Given data:
Mass of cobalt = 20 g
Half life = 5.26 years
Mass remain after 10.52 years = 5 g
Solution:
Number of half lives = T elapsed / half life
Number of half lives = 10.52 years / 5.26 years
Number of half lives = 2
At time zero = 20 g
At first half life = 20 g /2 = 10 g
At second half life = 10 g/2 = 5 g
The given statement is true.
