Answer;
1600 years
Explanation;
- Half life is the time taken for a radioactive isotope to decay by half of its original amount.
- We can use the formula; N = O × (1/2)^n ; where N is the new mass, O is the original amount and n is the number of half lives.
- A sample of radium-226 takes 3200 years to decay to 1/4 of its original amount.
Therefore;
1/4 = 1 × (1/2)^n
1/4 = (1/2)^n
n = 2
Thus; 3200 years is equivalent to 2 half lives.
Hence, the half life of radium-226 is 1600 years
