Types of Radiation
Radiation comes in two types. Particle and Energy.
Particle radiation is sub atomic particles, or atoms that careen through space and because they have a lot of kinetic energy, when they interact with other matter they disrupt it, damaging cells in organisms large and small.
An alpha particle is a helium ion that carries a large mass (4 amu) and charge (+2) and therefore is very likely to interact with any matter that it comes in contact with. Because it is large and highly charged, its penetrating ability, how deeply it will enter matter in which it comes into contact with, will be less than a particle with less charge. Therefore it is very easy to shield for, and can be blocked with a sheet of paper.
Beta radiation comes in two forms: B-and B+ . B- radiation occurs when a nucleus has too many neutrons, and one neutron gives off an electron. Due to the conservation of charge, that causes the neutron to become a proton. This process causes the atom to transmutate, become another element, since it now has more protons than it had previously, and protons determine the element.
B+ occurs when there are too many protons in the nucleus, and not enough energy, known as binding energy per nucleon, to keep the nucleus together. As a result, the nucleus emits a particle with a positive charge that in turn causes the number of protons in the nucleus to decrease, and the number of neutrons to increase. This particle is known as a positron and is the anti-particle of the electron. The term anti-particle just implies that the particle has the same mass as an electron, but the opposite charge. So a positron is just a + electron. Once again transmutation occurs, and the new nucleus, known as a daughter nucleus, is a new element.
Since it has a very small mass, the beta particle doesn't carry a lot of energy so it will do only minimal damage and because it has a charge, its penetrating ability is limited, like the alpha particle. Beta particles can be blocked by the top, dead layer of the skin.
A neutron is a sub-atomic particle that has a relatively high mass (1 amu) (in comparison to our B particles) and no charge. Since it has a relatively high mass, when it smashes into other matter at high speeds, it will do quite a bit of damage. Since it has no charge, it is also very penetrating, so neutron radiation is some of the deadliest radiation
Gamma radiation will not turn you into a green hulking monster. No, gamma energy will turn you into a decomposing mass of sores and burns. Gamma radiation is electromagnetic waves, you know, the same stuff light is made out of. It is a packet of electromagnetic energy with very small wavelength and very high frequency. These light packets, known as photons (yes, like photon torpedoes, for you Star Trek fans out there), have momentum just like moving matter would. Their energy is independent of the speed since all light travels at the same speed through a medium, and is dependent upon the frequency... the higher the frequency, the higher the energy.