The Basics of Radioactivity – The Alpha Particle
In the Boy Scout Atomic Energy Merit Badge book from 1984, it first states that a Boy Scout should be able to tell the meaning of the following items: alpha-particle, atom, background radiation, beta particle, curie, fallout, half-life, ionization, isotope, neutron, neutron activation, nuclear energy, nuclear reactor, particle accelerator, radiation, radioactivity, roentgen and x-ray.
Today we are going to learn about the alpha particle. It may also be referred to as an alpha ray or alpha radiation. In the most basic sense, an alpha particle. The alpha particle is identical to the nucleus of a Helium-4 (He) atom, consisting of two protons and two neutrons bound together in a particle.
Alpha particles are a form of nuclear radiation and can be deadly if ingested. Once internal, alpha radiation is the most destructive form of ionizing radiation. Alpha particles can be completely shielded by a half-inch of paper or 1cm of plastic. In most cases, a small amount of distance from the source will provide sufficient shielding with no paper/plastic/glass/lead needed.
Alpha particles (Americium (Am) 241) are used commonly in household smoke detectors and have saved thousands of lives by alerting people of a fire in their building.