One mole of `alpha` emitter of half life equal to `2` days was placed in a sealed tube for `4` days at `S.T.P` volume of helium collector is

One gram of a radioactive substance of half life 4 days is sealed in a tube. The quantity left after 5 days is

1 g atom of an alpha -emitting ._(z)X^(4) (half life = 10 hr) was placed in sealed containers, 4.52 xx 10^(25) . Helium atoms will accumulate in the container after

1 g atom of an alpha -emitting ._(z)X^(4) (half life = 10 hr) was placed in sealed containers, 4.52 xx 10^(25) . Helium atoms will accumulate in the container after

One mole of a gas at S.T.P. occupies volume ____.

One mole of a gas at S.T.P contains molecules equal to ____.

A certain radioactive isotope decay has alpha -emission, ._(Z_(1))^(A_(1))X to ._(Z_(1)-2)^(A_(1)-4)Y half life of X is 10 days. If 1 mol of X is taken initially in a sealed container, then what volume of helium will be collected at STP after 20 days?

A radioactive sample is alpha- emitter with half life 138.6 days is observed by a student to have 2000 disintegration/sec. The number of radioactive nuclei for given activity are.

A radioactive sample is alpha- emitter with half life 138.6 days is observed by a student to have 2000 disintegration/sec. The number of radioactive nuclei for given activity are.