Obtain the amount of `"_27^60Co` necessary to provide a radioactive source of 8.0 mCi strength. The half-life of `"_27^60Co` is 5.3 years.

Distinguish between isotopes and isobars. Give one example for each of the species. A radioactive isotope has half life of 5 years. How long will it take the activity to reduce to 3.125%.

A piece of wood from an archaeological source has a "^14C activity which ls 60% of the activity found in fresh wood today. Calculate the age of the archaeological sample (the half life period of C-14 is 5770 years).

Calculate the volume occupied by 4.4 g of CO_2 at 27^@C and under a pressure of 0.5 atmosphere.

A small quantity of solution containing Na^24 radio nuclide (half-life=15 h) of activity 1.0 microcurie is injected into the blood of a person. A sample of the blood of volume 1cm^3 taken after 5h shows an activity of 296 disintegrations per minute. Determine the total volume of the blood in the body of the person. Assume that the radioactive solution mixes uniformly in the blood of person. ( 1 curie =3.7 xx 10^10 disintegrations per second)

A solenoid 60 cm long and of radius 4.0 cm has 3 layers of windings of 300 turns each. A 2.0 cm long wire of mass 2.5 g lies inside the solenoid (near its centre) normal to its axis, both the wire and the axis of the solenoid are in the horizontal plane. The wire is connected through two leads parallel to the axis of the solenoid to an external battery which supplies a current of 6.0 A in the wire. What value of current (with appropriate sense of circulation) in the windings of the solenoid can support the weight of the wire? g = 9.8 m s^-2 .

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) =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

Obtain the co-ordinates of the feet of perpendiculars drawn from the origin upon the lines 3x -5y + 2=0 and 4x- 3y + 5 = 0 and show that the equation of the st. line joining these feet is 26x + 53y = 11 .

In an experiment,the activity of 1.2 milligram(mg) of radioactive potassium chloride (chlroide of isotopeK_40) was found to be 170s^(-1) .Taking molar mass of K-40Cl to be 0.075 kg mole ^(-1),find the number of K-40 atoms in the sample and hence find the half-life of K-40 .Given ,Avogadro number =6.0 x 10^(23) mole^(-1).