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 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 activity.

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 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 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.

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.

Radon is a radioactive gas with half-life 56 s.For health reasons,the maximum permissible level of radon in air in a building is set a t 1 radon atom for every .15xx10^(21) molecules of air 1 mol of air in the building is contained in 0.024 m^3 .Calculate ,for this building the maximum permissible number of radon atom in 1.0 m^3 of air

Iron has a body centred cubic unit cell with the cell dimension of 286.65 pm. Density of iron ·is 7.87 g cm^(-3) Use this information to calculate Avogadro's number. (Atomic mass of Fe= 56.0 u)

Radon is a radioactive gas with half-life 56 s.For health reasons,the maximum permissible level of radon in air in a building is set a t 1 radon atom for every .15xx10^(21) molecules of air 1 mol of air in the building is contained in 0.024 m^3 .Calculate ,for this building the number of molecules for air in 1.0 m^3 .

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