a radioactive isotope has a half life of T years. how long will it take the activity to reduce 1% of its original value.

A radioactive isotope has a half life of T years. How long will it take the activity to reduce to 3.125% .

The half-life of a radioactive element is 1580 years. How long will it take to reduce to 1/4th of its original mass ?

The half life period of 1st order reaction of A is 2 minutes. How long will it take to reach at 25% of its initial concentration.

4 gram of a radioactive material of half life 10 years is kept for 15 years. How much of the material will disintegrate?

Define half life. 50% of a radioactive sample decays in 20 years. Find the half life and after how many years 75% of the material will decay.