Complete the table Half Life Decay Rate k 43 per year 0043

Complete the table. Half Life Decay Rate, k 4.3% per year = - 0.043 The half-life of a substance is approximately

Solution

Let the decay of substance be given by q(d)=a(1-.043)^d

=> (1/2)a = a(1-.043)^d

^=> (1/2)= (1-.043)^d = (.957)^d

=> log(1/2) = d×log(.957)

=> d = Half life = log(1/2)/log(.957)

=> d =(-0.3010299957/-0.0190880622) = 15.77 years (approx)