After one half life, the ratio of parent atoms to daughter atoms in a sample is 1:2.
True or False

Explanation:

                     As we know that half life of any substance is constant. The ratio of parent to daughter atoms after one half life will be 1:1, then after the second half life further half of the first half will decay and will produce more daughter and reduce more parent and making the ratio 1:3, the ratio after 3rd half life will be 1:7, then 1:15 and so on.

Let's suppose that we are given with 100 g of radioactive substance and we are calculating the mass of parent and daughter atoms after every half life as;

1/2 life             Mass of Parent             Mass of Daughter               Ratio

0                            100 g                                   0                            100:0

1                                50                                     50                            1:1

2                               25                                     75                             1:3

3                               12.5                                   87.5                           1:7

4                               6.25                                 93.75                         1:15

the answer for sodium is 0.186

the answer for rubidium is 0.251