What is an alpha particle?

The alpha particle is a type of ionizing radiation. With its partners the gamma particles and beta particles, alpha particles are one of the most prevalent forms of radiation. An alpha particle is essentially a helium nucleus, which consists of two neutrons and two protons, without electrons, giving it a net positive charge. Due to its relatively high mass, alpha particles are the most destructive form of ionizing radiation, but the trade-off is that their penetration is low. A piece of paper stops alpha particles, whereas the lighter beta particles require a aluminum barrier. Alpha particles are emitted from various radioactive substances. Unlike beta decay, alpha decay (the process whereby alpha particles are emitted from a radioactive nucleus) is mediated by the strong force. According to classical Newtonian laws, the attraction of the nucleus should be too strong to let alpha particles leave it under any circumstances. However, quantum tunneling permits it anyway. Quantum ...  more

An alpha particle is basically a helium atom with all the electrons stripped off of it. Because of this, it is very heavy (relatively speaking) and does not travel at high velocities, meaning that if it does penetrate, it's at VERY shallow depths. * Beta particles: Beta particles are much longer lived than alpha particles... they also can cause more damage to living tissue. There are two types of beta decay. Both involve free nuclear (proton, neutron) particles decaying into high energy (FAST) electrons or positrons and neutrinos (or antineutrinos, depending on which particle decays). Neutrinos (and antineutrinos) are a nonthreatening byproduct of the decay (in a given second, you have 2 x 1010/cm2/sec passing through you every second of every hour of every day. That's 20,000,000,000 neutrinos per square centimeter per second.) Even being in the same room with a neuclear reactor, though it increases your exposure to neutrinos by 100,000 times, is effectively safe. In short: neutrinos ...  more

What is a beta particle? An alpha particle is a helium nucleus. A beta particle is an electron. • What is meant by the half-life of a radioactive substance? The half life is the time it takes for one half of a given radioactive substance to decay. • What is spontaneous fission? Why is it important? Spontaneous fission is fission that occurs without any external trigger i.e. a neutron. It is important because neutrons are released in this process. Those neutrons can then trigger other fission reactions. If spontaneous fission were to occur just as two halves of a gun type weapon were being assembled there is a chance that the weapon will fizzle. • Iodine 131 is a prominent fallout particle. After undergoing beta decay what element does it become? I 131 → Xe 131 + b ; where Xe is xeonon. • When uranium 238 decays by alpha particle emission, what nucleus is formed? U 238 → Th 234 + a ; where Th is thorium. • Plutonium is usually the radioactive material used in the primary of a hydrogen ...  more