Rheumatoid arthritis (RA) is the second most common type of arthritis, affecting around 1.5 million Americans. A systemic autoimmune disease, it mainly attacks the synovial joints: the hands and wrists, shoulders, elbows, knees, ankles, feet, and toes.
Beta radiation, consisting of electrons or positrons, is halted by an aluminum plate. Gamma radiation is damped by lead. Beta particles are high-energy, high-speed electrons or positrons emitted by certain types of radioactive nuclei, such as potassium-40. The beta particles emitted are a form of ionizing radiation also known as beta rays. The production of beta particles is termed beta decay. They are designated by the Greek letter beta (Î²). There are two forms of beta decay, Î² â and Î² + , which respectively give rise to the electron and the positron.
Alpha, beta and gamma radiation can be emitted from any unstable nucleus of an atom. An alpha particle is essentially a helium nucleus. Under certain conditions, a large nucleus may give off these particles. An alpha particle is two protons and two neutrons. An alpha particle has a positive charge. An alpha particle in isotopic notation looks like this: Alpha particles are very large in comparison to beta and gamma. An alpha particle has very low penetrating ability. People can protect themselves against an alpha particle by using a sheet of paper, which will deflect the alpha particle. Human skin is not affected by alpha particles.