Radioactivity and radioactive decay are spontaneous processes.

According to the creator of The Simpsons, Matt Groening, the show adopted the concept of a large supporting cast from the Canadian sketch comedy show Second City Television.

There is no going back – the process is irreversible. When we pour our popcorn kernels into a popcorn popper, the is no way to know which will pop first.

And once that first kernel pops, it will never be a kernel again..is forever changed! ) Teaching example using popcorn to teach radioactive decay "A variety of a chemical element (strictly, of one particular element) which is distinguished from the other varieties of the element by a different mass number but shares the same atomic number and chemical properties (and so occupies the same position in the periodic table)." That definition may not mean anything to them.

Curie · Skłodowska-Curie · Davisson · Fermi · Hahn · Jensen · Lawrence · Mayer · Meitner · Oliphant · Oppenheimer · Proca · Purcell · Rabi · Rutherford · Soddy · Strassmann · Szilárd · Teller · Thomson · Walton · Wigner Radioactive decay (also known as nuclear decay or radioactivity) is the process by which an unstable atomic nucleus loses energy (in terms of mass in its rest frame) by emitting radiation, such as an alpha particle, beta particle with neutrino or only a neutrino in the case of electron capture, gamma ray, or electron in the case of internal conversion.

If there are multiple particles produced during a single decay, as in beta decay, their relative angular distribution, or spin directions may not be isotropic.