What type of decay does cobalt 60 undergo

Marie Curie and her husband Pierre Curie contributed further to the understanding of radioactivity. Their research led to the discovery of two new radioactive elements, polonium and radium, and forced scientists to change their ideas about the structure of the atom. Radioactivity is the result of an atom trying to reach a more stable nuclear configuration.

The process of radioactive decay, can be achieved via three primary methods; a nucleus can change one of its neutrons into a proton with the simultaneous emission of an electron beta decay , by emitting a helium nucleus alpha decay , or by spontaneous fission splitting into two fragments. There are very small amounts of Co in the environment from nuclear facilities. Nuclear Regulatory Commission regulations allow discharge of small amounts of Co from licensed facilities. Cobalt is used as a radiation source in many common industrial applications, such as in leveling devices and thickness gauges.

It is also used for radiation therapy in hospitals. Accidental exposures may occur as the result of loss or improper disposal of medical and industrial radiation sources. Though relatively rare, exposure has also occurred by accidental mishandling of a source at a metal recycling facility or steel mill. Most exposure to Co takes place intentionally during medical tests and treatments. Linear and angular momentum are conserved, too. Although conserved angular momentum is not of great consequence in this type of decay, conservation of linear momentum has interesting consequences.

If the nucleus is at rest when it decays, its momentum is zero. In that case, the fragments must fly in opposite directions with equal-magnitude momenta so that total momentum remains zero. Total mass—energy is also conserved: the energy produced in the decay comes from conversion of a fraction of the original mass.

This is easily done using masses given in Appendix A. The energy carried away by the recoil of the U nucleus is much smaller in order to conserve momentum. This decay is spontaneous and releases energy, because the products have less mass than the parent nucleus.

The question of why the products have less mass will be discussed in Binding Energy. Note that the masses given in Appendix A are atomic masses of neutral atoms, including their electrons. In this case, there are 94 electrons before and after the decay. There are actually three types of beta decay. The neutrino is a particle emitted in beta decay that was unanticipated and is of fundamental importance.

The neutrino was not even proposed in theory until more than 20 years after beta decay was known to involve electron emissions. Neutrinos are so difficult to detect that the first direct evidence of them was not obtained until Neutrinos are nearly massless, have no charge, and do not interact with nucleons via the strong nuclear force.

Traveling approximately at the speed of light, they have little time to affect any nucleus they encounter. This is, owing to the fact that they have no charge and they are not EM waves , they do not interact through the EM force. They do interact via the relatively weak and very short range weak nuclear force. Consequently, neutrinos escape almost any detector and penetrate almost any shielding. However, neutrinos do carry energy, angular momentum they are fermions with half-integral spin , and linear momentum away from a beta decay.

When accurate measurements of beta decay were made, it became apparent that energy, angular momentum, and linear momentum were not accounted for by the daughter nucleus and electron alone. Either a previously unsuspected particle was carrying them away, or three conservation laws were being violated. Wolfgang Pauli made a formal proposal for the existence of neutrinos in The Italian-born American physicist Enrico Fermi — gave neutrinos their name, meaning little neutral ones, when he developed a sophisticated theory of beta decay see Figure 3.

Figure 3. Enrico Fermi was nearly unique among 20th-century physicists—he made significant contributions both as an experimentalist and a theorist. His many contributions to theoretical physics included the identification of the weak nuclear force.

The fermi fm is named after him, as are an entire class of subatomic particles fermions , an element Fermium , and a major research laboratory Fermilab.

His experimental work included studies of radioactivity, for which he won the Nobel Prize in physics, and creation of the first nuclear chain reaction. The neutrino also reveals a new conservation law. There are various families of particles, one of which is the electron family. We propose that the number of members of the electron family is constant in any process or any closed system. In our example of beta decay, there are no members of the electron family present before the decay, but after, there is an electron and a neutrino.

The bar indicates this is a particle of antimatter. Co can occur as a powder if the solid sources have been ground or damaged. Because it decays by gamma radiation, external exposure to large sources of Co can cause skin burns, acute radiation sickness , or death. Most Co that is ingested is excreted in the feces; however, a small amount is absorbed by the liver, kidneys, and bones.

Co absorbed by the liver, kidneys, or bone tissue can cause cancer because of exposure to the gamma radiation. Skip directly to site content Skip directly to page options Skip directly to A-Z link. Radiation Emergencies. Section Navigation. Facebook Twitter LinkedIn Syndicate.