Related Terms. Ratio of the density of a substance at 20Â°C or 68Â°F to the density of water at 4Â°C or 39.2Â°F.
Nuclear fission. NUCLEAR FISSION. Nuclear fission is a reaction in which an atom's nucleus is broken apart, releasing a tremendous amount of energy. Nuclear fission is used in many power plants on Earth (and is used in atomic weapons). nuclear fission: Reaction that splits nuclei into less massive fragments.nuclear fusion: Reaction that joins the nuclei of atoms to form more massive nuclei. - (n.). The splitting of an atomic nucleus into two large fragments. nuclear fusion - (n.) ... ~ reactors naturally produce free neutron s; their role is to sustain the energy-producing chain reaction.
Both fission and fusion are nuclear processes by which atoms are altered to create energy, but what is the difference between the two? Simply put, fission is the division of one atom into two, and fusion is the combination of two lighter atoms into a larger one. They are opposing processes, and therefore very different. (Merriam-Webster Online, www.m-w.com). Nuclear fission releases heat energy by splitting atoms.