If `N_(0)` =1 gm then after how many half lives N t will be 0.25 gm ?

Consider a radioactive substance. The fraction of its quantity that remains after t half lives is given by 3^(-t) . After how many half lives will the fraction be 1/243 of the original?

A certain radioactive element has a half-life of 20 years . If we have a block with 10 g of the element in it, after how many years will there be just 2.5 gm of element in the block

How many GMM is present in 28 gm nitrogen?

If N_0 = number of atoms originally present (i.e at t = 0) N = Number of atoms present after n - half lives ( n = t/T) then n_0 , N and n are related as

Half life of a radioactive elemets is 12.5 hour and its quantity is 256 gm. After how much time is quantity will remain 1 gm ?

Half life of a radioactive elemets is 12.5 hour and its quantity is 256 gm. After how much time is quantity will remain 1 gm ?

How many GMM is present in 18 gm water?

The half-life of pononium is 140 days. After how many days. 16 gm polonium will be reduced to 1 gm (or 15 gm will decay) ?