One gram of a radiactive material having a half-life period of `2` years is kept in store for a duration of `4` years. Calculate how much of the material ramins unchanged.

One gram of a radiactive material having a half-life period of 2 years is kept in store for a duration of 4 years. Calculate how much of the material ramins uncahnged.

10 gm of radioactive material of half-life 15 year is kept in store for 20 years, The disintegrated material is.

4g of a radioactive material of half life 10 years is kept in a store for 15 years. How much material is disntegrated ?

If a radioactive material has half life of one year, a sample will be reduced to 1/8 of its mass in

A radioactive substance has a half-life of 1 year. The fraction of this material, that would remain after 5 years will be.

One gram of a radiactive substance takes 50 to lose 1 centigram. Find its half-life period.

The half-life period of radium is 1600 years. Calculate the disintegrationd of radium.

For a substance the average life for alpha- emission is 1620 years and for beta- emission is 405 years. After how much time the 1//4 of the material remains after alpha and beta emission ?

The radioactive isotope .^(137)Cs has a half life period of 30 years. Staring with 1 mg of .^(137)Cs . How much would remain after 120 years?