A radioactive nucleus can decay by two different processes. Half-life for the first process is 3.0 hours while it is 4.5 hours for the second process. The effective half-life of the nucleus will be:

How many alpha and beta particles are emitted when Uranium ₉₂U²³⁸ decays to lead ₈₂Pb²⁰⁶ ?

Which of the following figure represents the variation of $${l_n}\left( {{R \over {{R_0}}}} \right)$$ with $${l_n}A$$ (if R = radius of a nucleus and A = its mass number)

The ratio for the speed of the electron in the 3^rd orbit of He⁺ to the speed of the electron in the 3^rd orbit of hydrogen atom will be :