Question

Time during which the amount of radioactive substance becomes half of its initial amount is called

Answer 1

Hi....
Time in which the amount of radioactive substance becomes half its initial amount is called the ' Half Life '...

And its formula is t(half life) = ln2/k
Where k= decay constant....

Hope this helps you.... ☺️☺️

Answer 2

Half life is the time that a radioactive substance takes to become half of the initial quantity.

So obviously after half life has passed the radioactive substance will be half of its initial quantity.