Radioactivity

Radioactivity is the decay of unstable isotopes of an element.  Atoms with the same number of protons, but varying numbers of neutrons are said to be isotopes of one another.  There are several ways that this can occur.  They are called; alpha decay, beta decay, and gamma rays.  These three processes are similar in some ways and are different in other ways.  They are similar in that each of these processes results in an emission of radiation in one form or another.  They are different in the effects they have on the original element and/or its individual atoms or nuclei.

            Alpha decay emits what is called alpha particles which are relatively large and consists of two protons and two neutrons.  Uranium 238 for example has 92 protons.  When alpha decay is present the individual atoms lose two protons which lower the number of protons in the nucleus to 90.  Since the number of electrons is relative to the number of protons in an atom, two of the electrons are released.  The alpha particle is made up of two protons and two neutrons which is the same as a helium nucleus.  When this alpha particle acquires the two electrons that were released it becomes an atom of helium gas.  The original atom with its 90 protons becomes an entirely new element, which is thorium 234.

            In beta decay, the process involves the decay of the neutron and the emission of an electron and a neutrino.  The electron, however, is not part of the original atom and the neutrino is a particle of very small mass and carries a neutral electrical charge.  This process also changes the element’s chemical identity.  After this process the atom still has the same mass, but has one more proton and one less neutron, thus changing the identity into another element.  Carbon 14 for example after undergoing this process becomes nitrogen 14.

            Gamma radiation involves the nuclear quantum leaps of the protons or neutrons of an atom.  When this happens it is similar to the quantum leap of an electron except it emits about one million times the energy.  The resulting gamma radiation that is emitted is in the wavelengths of x-rays or even shorter wavelengths with more energy. 

References

Trefil, J. H. (2010). The Sciences: An Intigrated Approach. George Mason University.