In pair annihilation an electron and a position destroy each other to produce gamma radiations . How is the momentum conserved ?

In pair annihilation an electron and a positron destroy each other to produce gamma radiations . How is the momentum conserved ?

In pair annihilation, an electron and a positron destroy each other to produce gamma radiation. How is the momentum conserved?

State the speed of each of alpha , beta and gamma radiations.

Considering aiming a beam of free electrons towards free protons. When they scatter an electron and a proton cannot combine to produce a H-atom. (a) because of energy conservation (b) without simultaneously releasing energy in the form of radiation (c) because o momentum conservation (d) because of angular momentum conservation

It is possible for a photon to materialize into an electron and a position. The process is called pair production. (a) Using conservation of energy and momentum prove that pair production cannot occur in empty space. (b) Argue qualitatively that such pair production is possible near a nucleus.

Considering a hypotetical annihilation of a stationary electron with a stationary positron, the wavelength of resulting radiation ? (with usual notations)