Question

(i) Define ‘activity’ of a radioactive material and write its S.I. unit. 

(ii) Plot a graph showing variation of activity of a given radioactive sample with time. 

(iii) The sequence of stepwise decay of a radioactive nucleus is

If the atomic number and mass number of D₂ are 71 and 176 respectively, what are their corresponding values for D?

Answer 1

(i) The activity of a radioactive substance is the rate of decay or the number of disintegrations per second of the substance

(ii) 

(iii) The sequence is represented as 

(i) Given A - 4 =176 => Mass number of D, A =180 

(ii) Z -1 =71 => Atomic number of D, Z =72.