The half`-`life of a radioactive isotope is always. `…………………………`.

Define half-life of a radioactive substance.

The half-life of a radioactive isotope is 3 h. if the initial mass of the isotope was 300 g, the mass which remained undercayed in 18 h would be

The half life of a radioactive isotope is 44 days . In how many days 1.0 g will be reduced to 62.5 mg ?