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	Radioactivity Each atom has at least one isotope, many having a great number of isotopes. An isotope is a combination of neutrons and protons present in an atom. For a full lesson on isotopes and their notation, read the page at the previous link. One of the problems so often discussed about nuclear power is leakage of unstable or radioactive isotopes from a plant. Radioactivity means that an element loses its mass over time and becomes smaller. The amount of time over which an element will break down is independent for each isotope. Several different kinds of "break downs" occur within radioactive isotopes. Each process of radioactive decay asserts a different strength on the surrounding environment. This strength is termed radiation. The chemical equations for the decay procedure that exists in some isotopes are presented here: Type of Decay & Reaction Strength of Radiation Alpha, 23892U --> 42He + 23490Th Can be stopped by several sheets of ordinary paper or clothing. Beta, 146C --> 0-1Beta + 145B .125 inches of aluminum are needed to stop beta particles. Gamma, 4019K --> 00Gamma + 4019K Can pass through the human body. Thick lead or concrete are needed as protection. The amount of time it takes the element to decay to half of its mass is called an isotopes's half life. Different element's half lifes are measured in seconds or days or even years. Some of the half lifes of the elements involved in the nuclear decomposition reaction are shown in the following table: Radioactive Isotope, Type of Decay Half Life Carbon-14, beta decay 5730 years Uranium-238, alpha decay 4.47 * 109 years, or 4470000000 years Amercium-241, alpha decay 432 years Arsenic-74, beta decay 17.9 days Radioactive Series Some radioactive isotopes decay into other nonstable isotopes. This process can go on for a very long time, determined by the different half lifes of each of the isotopes. One of the largest radioactive series is 15 elements long! Its process is shown below: Isotope, Type of Decay Half Life U-238, alpha 109 years Th-234, beta 24 days Pa-234, beta 1.2 minutes U-234, alpha 105 years Th-230, alpha 104 years Ra-226, alpha 1622 years Rn-222, alpha 3.8 days Po-218, beta 3.0 minutes At-218, alpha 1.4 seconds Bi-214, beta 20 minutes Po-214, alpha 164 microseconds Pb-210, beta 21 years Bi-210, beta 5 days Po-210, alpha 138 days Pb-206 stable Several equation represent radioactivity. Because a half life is the amount of time that it takes for any radioactive isotope to lose half of its mass. Timespan * halflife = amount left Do these nuclear problems, and quiz yourself on these radioactive concepts.