A radiaocatice isotope is being produced at a constant rate `X`. Half-life of the radioactive substance is `Y`. After some time, the number of radioactive nuceli become constant. The value of this constant is .

Explanation

At the stage of radioactive equilibrium, Rate of formation of nuclide = Rate of decay of nuclide
`x = lambda N`
`N = (x)/(lambda) = (x)/(In 2)//y) = (xy)/(In 2)`