Half life of a radioactive substance is 6 minute. If its initial amount is 32g, then amount present after 18 minute is

Half-life of a radioactive substance is 18 minutes. The time interval between its 20% decay and 80% decay in minutes is

The half-life of radioactive material is 3 h . If the initial amount is 300 g , then after 18 h , it will remain

The half-life of a radioisotope is 1.5 hours. If its initial mass is 32g, the mass left undecayed after 6 hours is

what is the half -life of a radioactive substance if 75% of its given amount disintegrate in 60 min ?

The half life period of a radioactive substance is 15 minutes. What per cent of radioactivity of that material will remain after 45 minutes ?