unstable, radioactive
An atom whose nucleus decays over time is called radioactive. Some examples of radioactive substances are uranium, plutonium, and einsteinium.
Radioactivity
When an atom of 85Kr spontaneously decays, it emits a beta particle. This decay process involves the transformation of a neutron into a proton, with the emission of an electron and an antineutrino.
Tritium decay to helium-3.
The term for the element that a radioactive isotope decays into is called the "daughter product". During radioactive decay, the original isotope transforms into a different element or isotope through a series of decay reactions.
entropy
If an atom that emits a green proton when it decays to its ground state decays to an intermediate state instead it will emit a proton that is yellow/orange/red. The reason is that it will be a lower energy proton emitted and lower energy waves correspond to longer wavelengths like the ones that make up these colors.
according to google XD, this is the radioactive atom that decays to product a daughter isotope
That's what an atom emits when it decays.
Th-230 -> He-4 + Ra-226 Thorium which alpha decays produces an alpha particle (Helium 4) and a Radium-226 atom.
The universe is chaotic. As every atom was formed, eventually every atom will fall apart. Every atom decays, although some at very very slow rates.
Though the electron itself is not present in the nucleus of an atom, the elementary particles that make up the electron are present inside the neutron. In other words, a neutron is made up of an electron and a proton. How do we know this? Because when a neutron decays, it slowly decays into a proton and an electron. It's a cycle.