75 atoms of radio active species are decayed in 2 half lives (`t""_(1//2)=1hr`) if 100 atoms are taken initially. Number of atoms decayed if 200 atoms are taken in two hours are

Radioactive decay is a statisticle process i.e., we cannot precisely predict the timing of a particular radioactivity of a particular nucleus . The nucleus can disintegrate immediately or it may take infinite time . Simply the probability of the number of nuclei being disintegrated at any instant can be predicted . the rate at which a particular decay process in a radioactive sample is directly proportional to the number of radioactive nuclei present and thus obeys first order kinetics . the factor dN/N expresses the fraction of nuclei decayed in time dt. t_(1//2) is the time in which half of the atoms are decayed and average life is the time for the nucleus to survive before decay . 75 atoms of a radioactive species are decayed in 2 half lives (t_(1//2) = 1 hr ) if 100 atoms are taken initially . Number of atoms decayed if 200 atoms are taken in 2 hr are :

The half-life of a sample of a radioactive substance is 1 hour. If 8 xx 10^10 atoms are present at t = 0 , then the number of atoms decayed in the duration t = 2 hour to t = 4 hour will be

The half-life of a sample of a radioactive substance is 1 hour. If 8 xx 10^10 atoms are present at t = 0 , then the number of atoms decayed in the duration t = 2 hour to t = 4 hour will be

The radioactive sources A and B of half lives of t hr and 2t hr respectively, initially contain the same number of radioactive atoms. At the end of t hours, their rates of disintegration are in the ratio:

The radioactive sources A and B of half lives of 2 hr and 4 hr respectively, initially contain the same number of radioactive atoms. At the end of 2 hours, their rates of disintegration are in the ratio :

A radio active substance has a half life period of 30 days. Calculate (i) time taken for 3//4 of original number of atoms to disintegrate, (ii) time taken for 1//8 of the original number of atoms to remain unchanged.

The activity of a radioactive susbtance is R_(1) at time t_(1) and R_(2) at time t_(2) (>t1). its decay constant is λ. Then, number of atoms decayed between time interval t_(1) and t_(2) are

In problem 43 , number of atoms decayed between time interval t_(1) and t_(2) are

The graph between number of decayed atoms N' of a radioactive element and time t is.