This film focuses on the radioisotope; the radioactive isotope of an element. It was produced with the cooperation of the U.S. Atomic Energy Commission and its contractors (:23). It opens with a quote from Democritus (:40) as well as a man searching for gold in a river (1:03). Today, scientists hunt for minerals such as gold and silver in addition to others such as uranium (1:08). Uranium is a radioactive metal discovered through the use of a Geiger counter (1:20). Scientists believed it would eventually be able a viable power source (1:42), though this would take years of extensive research. The nuclear reactor and incubator of plutonium was a precursor to atomic power plants (1:51). Atomic energy was also the source of radioisotopes (1:58). A diagram of an atom is shown which is the basic unit of matter and within it, electrons revolve around a central nucleus (3:11). The nucleus is composed of protons and neutrons (3:24) and the proton carries a unit of positive charge whereas the neutron carries no charge and the electron carries a negative charge (4:06). Charge is dictated in subscript while the mass is dictated in superscript (4:20). The designation for Helium is provided (4:42) as well as for hydrogen and lithium (5:24). All atoms of the same elements have the same number of protons though in most elements there exists variations in the number of neutrons (5:45). These variations are known as isotopes which have different mass numbers (6:26). Cobalt is an example of an element which only has one true form though most have variations (6:56). At higher atomic numbers, the ratio gap between neutrons to protons becomes wider (7:45). This ratio is demonstrated on a graph (5:13). The positions pointed to represent the atoms with a stable number of neutron to proton rates (8:50) while the empty spaces represent atoms with an unstable amount of each (8:58). All atoms aim to reach a point of stability (9:49) and all the atoms after 83 are unstable isotopes (10:07). These return to stability through the process of radioactive decay (10:19). An example is provided of uranium as it goes through this process throwing off either an alpha or a beta particle at each step (11:01) until it becomes stable lead (13:34). The number of atoms decaying over time in a sample of radioactive isotopes is called the activity of that sample (14:46). The activity or rate of decay is measured in millicuries (14:53). A graph (15:26) is provided showing the rate of decay as well as the standard formula which is derived from this for radioactive decay (16:38). Half-life is when the rate of activity is equal to half that of the activity initially present (17:42) and this continues to break down in successive half-lives. Isotope literature is used to provide figures on half lives of specific isotopes (18:29). Carbon 14 takes 5,740 years to break down into Nitrogen (18:54). Einstein’s formula which shows that energy and mass are equal follows (22:05). Energy released during the breakdown is known as kinetic energy (22:28). Additional energy is released as a form of electromagnetic energy known as gamma radiation (22:41). A few radioactive isotopes which have long half lives include rhenium 187, potassium 40 and rubidium 187, and all of these only have one step to go prior to becoming stable isotopes (24:16). The formula for positron decay (26:44). At times, the electrons from the K-shell are captured by the nucleus and are then absorbed by a proton in a transformation known as K electron capture (27:45). The empty spaces in each orbit are filled by electrons from out lying orbits (28:07) and x-rays are released during this transfer (28:23). Energy can be emitted through positrons; gamma rays and beta particles and this emission of energy and decay happens at each step of the process (30:01). A demonstration follows of an atom of uranium 235 (30:22) showing the nucleus in a constant state of agitation (30:33). At least one atom becomes more and more unstable until splitting (30:55) and this is known as spontaneous fission (31:19). If enough uranium is present, one of the neutrons can strike and be absorbed by another nucleus thus continuing the process of fission (32:38). This chain reaction is similar to what happens in an atomic bomb (32:46). Graphite or other light substances can slow down the collision process (32:59), though if there is not enough graphite, neutrons tend to escape and with a certain large enough amount the reaction can sustain itself (34:06).

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