If an isotope of some element has a half of 300 years about how much of the isotope will be in sample after 300 years
If the half life is 300 years, after 300 year The mass of the sample will be half of whatever the initial mass of the substance was
A half-life is how long an isotope takes to break down. A 300 year half life means that half of the sample will be left after 300 years.