Neutron capture is a process in which a neutron collides with a nucleus and becomes part of this nucleus caused by nuclear forces. It interacts without release of another heavy particle. A gamma ray photon is emitted as an immediate result of the neutron capture process. Through the neutron capture the nucleus becomes a heavier isotope of the same element. The kind of decay depends on the isotope and its stability.
This process is for example part of the neutron activation analysis, in which a sample is positioned in a neutron beam and also used in the 'boron neutron capture therapy'.

See also Thermal Neutrons, Epithermal Neutron, Neutron Activation Analysis, Nuclear Charge Number, Deuteron, Isomeric Transition, Isotones, N P Reaction.

There are two kinds of beta decay: beta minus and beta plus decay. The differentiation depends on the charge of the emitted particle.
At the beta plus decay in the nucleus a proton changes to a neutron and emits a positron and a neutrino. The atom is after the decay a different element, but with the same number of particles in the nucleus.
At the beta minus decay in the nucleus a neutron changes to a proton and emits an electron and an antineutrino. As with the beta plus decay the atom changes to a different element but with the same number of particles in the nucleus.
Sometimes the electron capture is mentioned as a third kind of beta decay.
Beta decay is used for example in positron-electron tomography or in iodine-131 therapy.

See also Electron Capture.