Connor's Blog: Atomic Era

All substance is made of atoms. These have electrons (e) around the outside, and a nucleus in the center. The nucleus consists of protons (p) and neutrons (n), and is extremely small (Atoms are mostly made of empty space). In some atoms, the nucleus is unstable, and will decay into a more stable form. This type of radioactive decay is completely natural, unlike that of a nuclear power station (where neutrons speed around and hit uranium nuclei, causing them to split). You can heat the substance up, subject it to high pressure or powerful magnetic fields - basically, you can do pretty much whatever you like to it - and you won't affect the rate of decay.

Alpha particles are made of 2 protons and 2 neutrons. This means that they have a charge of +2, and a mass of 4 (measured in "atomic mass units") (each proton & neutron=1).Alpha particles are relatively slow and heavy. They have a low penetrating power, so even just a sheet of paper can stop them. Because they have a large charge, alpha particles ionize other atoms intensely.

Beta particles have a charge of minus 1, and a mass of about 1/2000th of a proton. This means that beta particles are the same as an electron, fast and light. Beta particles have a medium penetrating power, and can be stopped by a sheet of aluminum or plastics. Beta particles ionize atoms that they pass, but not as strongly as alpha particles do.

Gamma rays are waves, not particles. This means that they have no mass and no charge. Gamma rays have a high penetrating power; it takes a heavy sheet of metal such as lead, or concrete to reduce them significantly. Gamma rays do not directly ionize other atoms, although they may cause atoms to emit other particles which will then cause ionization. Pure gamma sources are not to be found seeing as gamma rays are emitted alongside alpha or beta particles. Strictly speaking, gamma emission isn't “radioactive decay” because it doesn't change the state of the nucleus; it just takes away some energy.

Fusion power is power generated by nuclear fusion processes. During fusion reactions, two light, atomic nuclei fuse together to form a heavier nucleus (in contrast with fission power). In doing so they release a comparatively large amounts of energy, as a byproduct, from the binding energy due to the strong nuclear force which is expressed as an increase in temperature of the reactants.

Nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts (lighter nuclei), often producing free neutrons and photons (in the form of gamma rays), and releasing a tremendous amount of energy. Most fission is binary fissions, but occasionally, three positively charged fragments are produced in a ternary fission. Fission is usually an energetic nuclear reaction induced by a neutron. The unpredictable make-up of the products (which vary in a broad probabilistic and somewhat chaotic manner) distinguishes fission from fusion.