Question

Half-Life Complete the table shown to the right for the half-life of a certain radioactive substance. Decay Rate, k 4.6% per year = -0.046 The half-life is years. (Round to one decimal place as needed.)

Answer 1

Let N(t) be the quantity of radio active substance at any timet. Suppose there was initially 1g of N(1) That is N(O)= 1 Given k=-0.046 To find half life period of N Now by using law of grouth and decay N(t)= S(0) * N(t)= e908ột (1) Put N = in (1), we get 1 -0.0160 2 -0.046t = in 2 (0) () 1 In 0.046 2 = 15.1 Hence the half life period of the given substance is t = 15.1y years

Answer 2

Complete the table shown to the right for the half-life of a certain radioactive substance.

4.3% per year= -0.043