Strontium-90 decays with the emission of a `beta-` particle to form Ytrium-90 .The reaction is represented by the equation
`_(38)Sr^(90) rarr _(39)Y^(90) + _(-1)e^0 + 0.55 MeV` the decay constant is `0.025 year ^(-1)`.
Suggest,with a reason,which nucleus `_(38)Sr^(90)` or `_(39)Y^(90)`,has the greater binding energy.

Strontium-90 decays with the emission of a beta- particle to form Ytrium-90 .The reaction is represented by the equation _(38)Sr^(90) rarr _(39)Y^(90) + _(-1)e^0 + 0.55 MeV the decay constant is 0.025 year ^(-1) . At the time of purchase of a Stronituim-90 source the activity is 3.7 xx 10^6 Bq . Calculate ,for this sample of strontium,the initial number of atoms.

Strontium-90 is a radioactive isotope having a half-life of 28 years.Calculate the decay constant lambda(in s^(-1)) of Strontium-90,

The isotope Manganese-56 decays and udergoes beta- particle eission to form the stable isotope Iron-56 .The half life for this decay is 2.6 hours .Initially,at time t=0,a sample of Manganese-56 has a mass of 1.4muG and there is no iron - 56. Determine the time at which the ratio is equal to 9.0.

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

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) =initial no. of nuclei. The above equation after integration can be represented as lambda=(2.303)/(t)log((N_(0))/(N)) Half-life period of U is 2.5xx10^(5) years. In how much time will the amount of U^(237) remaining be only 25% of the original amount ? a) 2.5xx10^(5) year b) 1.25xx10^(5) years c) 5xx10^(5) years d) none of these

A magnetic field set up using Helmholtz coils is uniform in a small region and has a magnitude of 0.75 T. In the same region, a uniform electrostatic field is maintained in a direction normal to the common axis of the coils. A narrow beam of (single species) charged particles all accelerated through 15 kV enters this region in a direction perpendicular to both the axis of the coils and the electrostatic field. If the beam remains undeflected when the electrostatic field is 9.0 xx 10^5 V m^-1 make a simple guess as to what the beam contains. Why is the answer not unique?

One end of a long string of linear mass density 8.0 xx 10^-3 kg m^-1 is connected to an electrically driven tuning fork of frequency 256 Hz. The other end passes over a pulley and is tied to a pan containing a mass of 90 kg. The pulley end absorbs all the incoming energy so that reflected waves at this end have negligible amplitude. At t= 0, the left end (fork end) of the string x = 0 has zero transverse displacement (y = 0) and is moving along positive y-direction. The amplitude of the wave is 5.0 cm. Write down the transverse displacement y asfunction of x and tthat describes the wave on the string

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.

Two concentric ellipses are such that the foci of one are on the other and their major axes are equal. Let ea n de ' be their eccentricities. Then. the quadrilateral formed by joining the foci of the two ellipses is a parallelogram the angle theta between their axes is given by theta=cos^(-1)sqrt(1/(e^2)+1/(e^('2))=1/(e^2e^('2))) If e^2+e^('2)=1, then the angle between the axes of the two ellipses is 90^0 none of these