NATS 1945 Lecture Notes - Lecture 4: Radioactive Decay, Decay Energy, Low Mass
6 Feb 2017
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Document Summary
Radioactivity or radioactive decay is the spontaneous explosion of an atom"s nucleus: nucleons: are particles that are either a proton or a neutron. A radioactive substance has atoms which naturally decay due to an imbalance among the forces between nucleons: the nuclear force: is possessed by all nucleons and is what holds the nucleus together. Half-life: time required for exactly half of an atom"s population to decay: **the shorter the half-life, the more radioactive the atom, because more of the atom"s population decays per second or the rate of decay is higher. Since a radioactive atom"s population is halved evert t1/2, the substance becomes less radioactive over time because less of the material is present. Radioactive dating: determining a substances age by its amount of radioactive decay. This method is used for dating rocks, fossils, and impact craters all over the world. Radiation: high-speed particles or high-energy light waves: radioactive decay is a source of radiation.
