The half-life of a radioactive substance is 100 years. Calculate in how many years the activity will decay to `1//10^(th)` of its initial value.

The half-life of a radioactive substance is 100 years, Calculate in how many years the activity will decay to 1/10th of its initial value.

The half-life of a radioactive substance is 5000 years. In how many years, its activity will decay to 0.2 times of its initial value ? Given "log"_10 5 = 0.6990.

The half-life of a radiaoactive substance is 100 years. In how many years its activity will deacy to 10% of its initial value?

The half-life of a radioactive substance is 5000 years. In how many years, its activity will decay to 0.2 times alpha its initial value ? Given log_(10)5=0.6990 .