Often accompanying alpha and beta radiation is gamma radiation. However, unlike alpha and beta radiation, gamma radiation is only energy and has no mass or particles. During alpha and beta decay, which is discussed in more detail in the previous Nuclear 101 segment, the nucleus is attempting to stabilize itself by releasing particles. Gamma radiation brings the nucleus from a higher energy state to a lower energy state by releasing excess energy from the nucleus. Gamma rays are high energy photons of electromagnetic radiation. In other words, gamma rays are packets of light energy released from an atom's nucleus. Radio waves and x-rays are examples of other types of electromagnetic radiation. However, gamma rays have a very short wavelength and thus they travel fast and with a great deal of energy. The emission of gamma radiation does not affect the number of protons in the nucleus and therefore this process does not change the element. Radioactive decay occurs when an atom's nucleus has more energy than its binding force can contain (refer to the Nuclear 101 segment on Radioisotopes for further explanation). Gamma radiation can aid in stabilizing the atom by lowering the energy state of the nucleus.
Neutron radiation is a byproduct of nuclear fission and fusion which are reactions that take place during the development and use of nuclear energy and nuclear weapons. The processes of nuclear fission and nuclear fusion will be discussed in a later segment of Nuclear 101. During fission and fusion, highly energized neutrons are released and are often absorbed by the nucleus of a nearby atom. The addition of energy into the nucleus can send the atom into an excited state and sets off a chain reaction as atoms absorb and emit radiation creating a highly radioactive environment. Neutron radiation can be disastrous to human organs and can cause cellular mutations.
Substances high in hydrogen content, such as water, can be successful in stopping neutron radiation. Alpha, beta, gamma, and neutron radiation are considered ionizing radiation. This means these particles (alpha, beta, neutron radiation) or energy (gamma rays) have the ability to actually knock the electrons off the orbits of those atoms they interact with. Hydrogen atoms are an example of atoms affected by radiation. The interaction that radioactive particles and energy have with hydrogen can actually break the chemical bonds of the radioactive particles thereby stopping them. This is why substances with high hydrogen content such as water are good shields against radiation.