Consider a radioactive nucleus A which decays to a stable nucleus C throught the following sequence:
`A rarr B rarr C`
Here B is an intermediate nucleus which is also radioactaive. Considering that there are `N_0` atoms of A initially, plot the graph showing the variaton of number of atoms of A and B versus time.

A radioactive nucleus X decays to a nucleus Y with a decay constant lambda_X=0.1s^-1, Y further decays to a stable nucleus Z with a decay constant lambda_Y=1//30s^-1 . Initially, there are only X nuclei and their number is N _0=10^20 . Set up the rate equations for the populations of X, Y and Z. The population of Y nucleus as a function of time is given by N_Y(t)={N _0lambda_X//(lambda_X-lambda_Y)}[exp(-lambda_Yt)-exp(-lambda_Xt)]. Find the time at which N_Y is maximum and determine the population X and Z at that instant.

A radioactive nucleus undergoes a series of decays according to the sequence, A overset (beta) rarr A_1 overset (alpha) rarr A_2 overset (alpha) rarr A_3 If the mass number and atomic number of A_3 are 172 and 69 respectively,what is the mass number and atomic number of A?

The half - life period of radioactive element A is the same as the mean life time of another radioactive element B. Initially both of them have same number of atoms. The radioactive element B decays faster than A. Explain, why.

Consider a reaction A+B rarr C , in which both reactants are in the same phase, may be a) unimolecular elementary reaction b) Exothermic c) Heterogeneous d) Photochemical

Fig 1.11 show the distance - time graphs of three A,B and C. Study the graph and answer the following question : Which of the three is travelling the fastest ?

Radioactive disintegration is a first order reaction and its rate depends only upon the nature of nucleus and does not depend upon external factors like temperature and pressure. The rate of radioactive disintegration (Activity) is represented as -(dN)/(dt)=lambdaN Where lambda= decay constant, N= number of nuclei at time t, N_(0) =intial no. of nuclei. The above equation after integration can be represented as lambda=(2.303)/(t)log((N_(0))/(N)) Calculate the half-life period of a radioactive element which remains only 1//16 of its original amount in 4740 years: a) 1185 years b) 2370 years c) 52.5 years d) none of these

Radioactive disintegration is a first order reaction and its rate depends only upon the nature of nucleus and does not depend upon external factors like temperature and pressure. The rate of radioactive disintegration (Activity) is represented as -(dN)/(dt)=lambdaN Where lambda= decay constant, N= number of nuclei at time t, N_(0) =intial no. of nuclei. The above equation after integration can be represented as lambda=(2.303)/(t)log((N_(0))/(N)) What is the activity in Ci (curie) of 1.0mole plutonium -239 ? (t_(1//2)=24000 years) a) 1.49 Ci b) 14.9 Ci c) 5.513xx10^(11) Ci d) None of these

The question given below consist of an assertion (A) and a reason ( R). Use the following key to choose the appropriate answer to these questions from the codes (a), (b), ( c) and (d) given below: (a) Both A and R are true and R is the correct explanation of A. (b) Both A and R are true but R is NOT the correct explanation of A. (c) A is true but R is false. (d) A is false and R is also false. Assertion: An atom behave as a magnetic dipole. Reason: Because an atom contains equal number of positive and negative charges.

Consider the following statements: A- Both acids and bases change colour of all indicators. B-If an indicator gives a colour change with an acid, it does not give a change with a base. C- If an indicator changes colour with a base, it does not change colour with an acid. D-Change of colour in an acid and a base depends on the type of the indicator. Which of these statements are correct?