Alpha decay of the The sum of the mass numbers of the products (234 + 4) is equal to the mass number of the parent nuclide (238), and the sum of the charges on the products (90 + 2) is equal to the charge on the parent nuclide.Nuclei can also decay by capturing one of the electrons that surround the nucleus.He argued that a neutron could decay to form a proton by emitting an electron.
The product of this reaction can be predicted, once again, by assuming that mass and charge are conserved. They rapidly lose their kinetic energy as they pass through matter.
As soon as they come to rest, they combine with an electron to form two -ray photons in a matter-antimatter annihilation reaction.-decay are often obtained in an excited state.
The excess energy associated with this excited state is released when the nucleus emits a photon in the -ray portion of the electromagnetic spectrum.
Most of the time, the -ray is emitted within 10Nuclides with atomic numbers of 90 or more undergo a form of radioactive decay known as spontaneous fission in which the parent nucleus splits into a pair of smaller nuclei.
Alpha decay is usually restricted to the heavier elements in the periodic table.