Deccay Rate

The count rate of a Geiger Muller counter for the radiation of a radioactive material of half-life of 30 minutes decreases to 5 second after 2 hours. The initial count rate was

Half-life for radioactive is 5760 yr. In how many years, 200 mg of will be reduced to 25 mg?

Half life of radioactive element is 12.5 Hour and its quantity is 256 gm. After how much time its quantity will remain 1 gm : -

Two radioactive materials , and have decay constants 5 and respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of X to that X will be 1/e after a time

The decay constant of a radio isotope is . If and are its activities at times and respectively, the number of nuclei which have decayed during the time

Two radioactive nuclei and , in a given sample decay into a stable nucleus . At time , number of species are and that of are . Half-life of (for conversion to ) is minute where as that of is minutes. Initially there are no nuclei of present in the sample. When number of nuclei of and are equal, the number of nuclei of present in the sample would be

The power obtained in a reactor using disintegration is . The mass decay of per hour is

Radioactive material has decay constant and material has decay constant Initially they have same number of nuclei. After what time, the ration of number of nuclei of material of material to that will be