Homework Solution

TQ 13-8

Given:

M_original = 10 g

t_1/2 = 5 days

t = 20 days

Find:

amount that would decay

Science:

M_remaining = M_original (1/2)ⁿ

n = t/t_1/2

Solve:

n = (20 days)/(5 days) = 4

M_remaining = (10 g) (1/2)⁴ = 0.625 g

M_decayed = M_{original -} M_remaining

M_decayed = 10 g - 0.625 g = 9.375 g _ANS