electron capture

noun physics

1. the transformation of an atomic nucleus in which an electron from the atom is spontaneously absorbed into the nucleus. A proton is changed into a neutron, thereby reducing the atomic number by 1. A neutrino is emitted. The process may be detected by the consequent emission of the characteristic X-rays of the resultant elementFormer name: K-capture
2. the spontaneous or induced recombination of free electrons with ions or by transfer from other atoms or ions