Beta decay is a form of radioactive decay that occurs in the nucleus of an unstable atom. Here, one of the neutron present in the nucleus of the atom gets transformed into a proton. As a result of the conversion, a new electron gets formed that is known as the beta particle. The beta particle tends to shoot out of the atom with a relatively high velocity. The main cause of a beta decay is the imbalance in the number of protons and neutrons present in the nucleus of the atom. In other words, if the number of protons present in the nucleus of an atom is lower than the total number of neutrons contained by it, then such an unstable atom is susceptible to exhibiting beta decay. The beta decay decreases the number of neutrons present in the nucleus and helps to establish balance in the number of neutrons and protons contained by the atom. As a result of beta decay, a beta particle and gamma radiations get released into the environment.
Types of Beta Decay
1. Beta Plus Decay
In the case of a beta plus decay, the nucleus of an unstable atom contains a proton that gets converted into a neutron, hence the number of protons tend to increase. Suppose that initially the total number of protons contained by the unstable atom is equal to z and the total number of neutrons is equal to n. After the atom of this particular radioactive element undergoes beta decay, the total number of protons contained by the nucleus is observed to be equal to z-1, while the total number of neutrons increases and becomes equal to n+1. Along with the change in number of protons and neutrons, a new positron and a neutrino gets formed. This means that the proton gets converted into a neutron, a positron, and a neutrino. The charge during the decay is required to be conserved, which is why the new element formed during the decay process is positively charged. This is the reason why such type of beta decay is called beta plus decay. The mass of a neutron is a little more than the mass of the proton, which is why the conversion of proton, i.e., a comparatively light weighed particle into the neutron, i.e., slightly heavy particle is not possible. The nucleons of the neutron however, help the neutron to undergo conversion and exhibit beta decay. The bonding between the protons and neutrons of the original atom is different from the bonding that exists between the protons and neutrons of the resultant atom, hence the mass of the resultant atom gets reduced. The energy is required to be balanced throughout the process, which is why formation of a positron and a neutrino takes place along with the release of kinetic energy.
2. Beta Minus Decay
In the case of a beta minus decay, the neutron of the atom gets transformed into a proton, hence the number of protons contained by the atom tend to increase. Suppose that initially the total number of protons of the unstable atom is equal to z and the total number of neutrons is equal to n. After the atom of this particular radioactive element undergoes beta decay, the total number of protons contained by the nucleus is observed to be equal to z+1, while the total number of neutrons decreases and becomes equal to n-1. Also, when the nucleus of an unstable atom of a radioactive element undergoes beta minus decay, two new elements get released as a product, i.e., an electron with a negative charge and an antineutrino particle. The mass of the antineutrino particle is quite small and it does not contain any charge. This type of beta decay is known as beta minus decay due to the availability of a negatively charged electron on the product side.
Examples of Beta Decay
There are a number of real-life applications that make use of beta decay. Some of them are listed below:
1. Particle Physics
Beta-decay is a process that takes place at nuclear level, hence it plays an important role in studying particle physics.
2. Manufacturing Industries
Manufacturing industries make use of beta decay of elements for a number of applications. For instance, the release of electrons and energy during the beta decay can be used to power a device or a gadget located in a remote place that is inaccessible to the workers. Also, it can be used to study the nature of the components and elements being used at a molecular level.
3. Medicinal Diagnostic and Cure
One of the most prominent applications of beta decay in real life can be seen in the field of medicine. A number of diagnostic and therapeutic gadgets used in hospitals and biology laboratories make use of beta decay of certain radioactive elements such as uranium, thorium, etc. A number of beta-emitting devices are used for cancer diagnosis and treatment purposes. For instance, therapies such as skin cancer therapy, radioimmunotherapy, bone-seeking radiopharmaceutical therapy, etc. make use of the beta decay. Beta-decay is also used in the radioactive tracers to identify the type and root cause of the health problem. Also, the beta decay of elements is helpful in vascular brachytherapy.
4. Decomposition of a Dead Organism
A dead organism buried inside the earth begins to get decomposed as time passes by. This happens due to the action of various microorganisms present beneath or above the surface of the earth. The application of beta decay in the decomposition of the body of a dead organism can be observed easily as here, the carbon element, i.e., C-14 begins to decay and gets transformed into nitrogen, i.e., N-14 followed by the emission of an electron into the environment.
Beta-decay is prominently used for surgical purposes. For instance, in the case of glaucoma surgery, beta decay or beta radiations are usually preferred.