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 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 is a radioactive isotope having a half-life of 28 years.Strontium-90 has a denstiy f 2.5 g cm^(-3) .A smaple of Strontium-90 has an activity of 6.4 xx 10^9 Bq .Calculate the mass of stronitium 90 in the sample

Strontium-90 is a radioactive isotope having a half-life of 28 years.Strontium-90 has a denstiy f 2.5 g cm^(-3) .A smaple of Strontium-90 has an activity of 6.4 xx 10^9 Bq .Calculate the volume of the sample.

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 Phosphorus-33 undergoes beta - decay to form Sulphur-33,which is stable.The half - life of Phosphorus-33 is 24.8 days. A pure sample of Phosphorus - 33 has an initial activity of 3.7 xx 10^6 Bq. Calculate the initial number of Phosphorus - 33 nuclei in the sample,

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. For the smple of Manganese-56 ,determine the initial number of Manganese-56 atoms in the sample an d

The isotope Phosphorus-33 (_(15)P^(33)) undergoes beta - decay to form "Sulphur"-33(_(16)S^(33)) ,which is stable.The half - life of Phosphorus-33 is 24.8 days. A pure sample of Phosphorus - 33 has an initial activity of 3.7 xx 10^6 Bq.Calculate the number of Phophorus - 33 nuclei remaining in the sample after 30 days.

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.

The nucleus of an atom of ._(92)Y^(235) initially at rest decays by emitting an alpha particle. The binding energy per nucleon of parent and dougther nuclei are 7.8MeV and 7.835MeV respectively and that of alpha particles is 7.07MeV//"nucleon". Assuming the dougther nucleus to be formed in the unexcited state and neglecting its share of energy in the reaction, calculate speed of emitted alpha particle. Take mass of alpha particle to be 6.68xx10^(-27)kg .

A small retangular coil ABCD contains 140 turns of wire. The sides AB and BC of the coil are of length 4.5 and 2.8 cm respectively, as shown in the figure The coil is held between the poles of a large magnet so that the coil can rotate about an axis thorugh its centre. The magnet produces a uniform magnetic field of flux density B between its poles. When the current in the coil is 170 mA, the maximum torque produced in the coil is 2.1 xx 10^-3 N m . The current in the coil in (a) is switched off and the coil s positioned as shown in the figure. The coil is then turned thorugh an angle of 90^@ in a time of 0.14 s. Calculate the average e.m.f. induced in the coil.