Answer:
6425 years
Explanation:
Half life refers to the time taken for a radioactive substance to decay to half of the original number of atoms present in the sample.
Some radioactive nuclides have short half lives while others have long half lives.
If 1 half life of Radium-226 is 1,285 years
Then, five half lives = 5 * 1,285 years = 6425 years
