Tritium with a half-life of 12.5 years undergoing beta decay. What fraction of a sample of pure tritium will remain undecayed after 25 years.

Spontaneous and continuous disintegration of a nucleus of a heavy element with the emissio of cer tain type os radiation is known as radioactivity. Tritium has a half-life of 12.5 years. What frac tion of a sample of pure tritium will remain undecayed after 50 years?

A radioactive sample has a half- life of 1500 years. A sealed tube contains 1 g of the sample. How much quantity of sample will be left after 3000 years?

The half life of a radioactive substance is 4.2 days. Find the time during which 1/8" of the sample will remain undecayed.

One of the harzards of nuclear explosion is the generation of ""^(90)Sr and its subsequent incorporation in bones. This nuclide has a half-life of 28.1 years. Suppose one microgram was absorbed by new born child, how much ""^(90)Sr will remain in his bones after 20 years.

The radioactive isotope tritum ( ""_(3)^(1)H) has a half life 0f 12.3 years. IF the initial amount of tritium is 32 mg, how many milligrams of it would remain after 49. 2 years ?

What fraction of the radioactive species (t_(1//2) = 12 "years") remains after six years ?