Physics Nuclei

In the given nuclear reaction, the elements X is: ${}_{11}^{22}\mathrm{N}\mathrm{a}\to \mathrm{X}+{\mathrm{e}}^{+}+v$

The decay of a proton to neutron is :

A radioactive sample disintegrates via two independent decay processes having half lives T?/?¹? and T?/?²? respectively. The effective half-life, T?/? of the nuclei is:

Given the masses of various atomic particles m? = 1.0072u, m? = 1.0087u, m? = 0.000548u, m? = 0, m? = 2.0141u, where p = proton, n = neutron, e = electron, v = antineutrino and d = deuteron. Which of the following process is allowed by momentum and energy conservation?

In a radioactive material, fraction of active material remaining after time t is 9/16. The fraction that was remaining after t/2 is

In a reactor, 2 kg of ₉₂U²³⁵ fuel is fully used up in 30 days. The energy released per fission is 200MeV. Given that the Avogadro number, N = 6.023 * 10²⁶ per kilo mole and 1eV = 1.6 * 10⁻¹⁹ J. The power output of the reactor is close to:
(A) 60MW

You are given that Mass of ?Li = 7.0160u, Mass of ?He = 4.0026u and ¹H = 1.0079u. When 20 g of ?Li is converted into ?He by proton capture, the energy liberated, (in kWh), is [Mass of nucleon = 1GeV/c²]

A radioactive nucleus decays by two difference processes. The half life for the first process is 10s$$ and that for the second is 100s${}^{}$ . The effective half life of the nucleus is closes to:

The activity of a radioactive sample falls from $700{\mathrm{s}}^{-1}$ to $500{\mathrm{s}}^{-1}$  in 30 minutes. Its half life is close to