The half-life period of a radioactive material is 5 hours. In how much time 15/16 of the material will decay?

The half-life period of a radioactive element is 140 days. After 560 days, 1 g of the element will reduce to

The half-life period of a radioactive element is 140 days. After 560 days, one gram of the element will reduce

The half life of a radioactive substance is 4.2 days. Find the time during which 1/8" of the sample will remain undecayed.

The half-life period of a first-order reaction is 15 minutes. The amount of substance left after one hour will be,