A radioactive sample has activity 80 Ci. It reduces to 10 Ci in 30 min, then the time taken for 160 Ci of the same element to reduce to 40 Ci is (in min)

If 20 gm of a radioactive substance due to radioactive decay reduces to 10 gm in 4 minutes, then in what time 80 gm of the same substance will reduce to 10 gm-

If 20 gm of a radioactive substance due to radioactive decay reduces to 10 gm in 4 minutes, then in what time 80 gm of the same substance will reduce to 10 gm ?

A radioactive sample has an activity of 5.13xx10^(7)Ci . Express its activity in 'becqueral' and 'rutherford'.

A radioactive sample has a half-life of 20 years. The time at which the activity of the sample will reduce to 10% of its initial value is

A radio active sample with a half life of 1 month has activity 2 mu ci .Its activity 2 months earlier was

A radioactive isotope has initial activity of 28 dpm Its activity is reduced to 14 dpm after half an hour. The initial number of nuclide in sample was:

A radioactive sample S_(1) having an acitivity of 5 mu Ci has twice the number of nuclei as another sample S_(2) which has a activity of 10 mu Ci . The half lives of S_(1) and S_(2) can be

The half-life period of a radioactive element is 1.4 xx 10^(10) years. Calculate the time in which the activity of the element is reduced to 90% of its original value.

A radioactive sample S_(1) having an activity 5 mu Ci has twice the number of inucle as another sample S_(2) which has as activity of 10 mu Ci . The half lives of S_(1) and S_(2) can be

The half life a radioactive element is 30 days, if the mass of the specimen reduces to 1//10^(th) then the time taken is :-