After two half-lives remaining is (1/2)^2 = 1/4, so disintegrated fraction = 1 - 1/4 = 3/4.
1882
(138) The lowest nucleon resonance state is the Δ which has a mass of 1232 MeV/c^2 and a width of 120 MeV. Calculate the lifetime of this I = 3/2 nucleon state:
Consider the hydrogen-like atom eigenvalue problem, one electron orbits a nucleus of charge Ze. The general wave function is Ψ_{n,l,m}(r,θ,φ)=R_{n,l}(r)Y_{l,m}(θ,φ). Determine the value of r where the radial probability is a maximum for the ground state.
The block header indicates option B as the answer; for the ground state the most probable radius for a hydrogen-like atom is at r = a_0/2 (with the given OCR answer key).
1884
The loss of mass in a.m.u. in a nuclear change can be calculated from energy involved in MeV by
Fusion releases energy when light nuclei combine to form a nucleus with mass number greater than ~50, so 'More Than 50' is correct.
1886
189. The rate of radioactive decay of a material is 800 disintegrations per second. If the half-life period of the material is 1 s, the rate of decay after 3 seconds will be
Annihilation of electron and positron typically produces two gamma photons, represented in the OCR as y + y.
1890
Consider the fission reaction in which two nuclei of same mass number 117 are produced plus two neutrons. The binding energy per nucleon of X and Y is 8.5 MeV whereas of U is 7.6 MeV; the total energy liberated will be about
