Nuclear Reactions

Types of Nuclear Reactions

Nuclear reactions happen when the nucleus of an atom is affected.
There are two major types of nuclear reactions: nuclear decay and nuclear transmutation.

Nuclear decay occurs when an unstable nucleus spontaneously changes, usually resulting in the emission of particles and energy.
There are three types of decay: alpha decay, beta decay, and gamma decay.
Alpha decay results in the emission of an alpha particle (2 protons and 2 neutrons) leaving a new element behind.
In beta decay, a neutron changes into a proton and emits a beta particle (an electron or positron).
Gamma decay usually follows alpha or beta decay, as an excess of energy is released from the nucleus in the form of gamma rays.

Nuclear transmutation is the conversion of one chemical element or isotope into another, due to a nuclear reaction or radioactive decay.
This type of reaction is responsible for the creation of many naturally occurring elements on Earth.
Typically, this involves bombarding a stable element with alpha particles, neutrons, or other atomic particles.
Nuclear fission, the splitting of a large atom into two or more smaller ones, and nuclear fusion, the joining of small atoms to form a larger one, are also forms of nuclear transmutation.

Nuclear reactions result in a large amount of energy being released or absorbed.
This is due to mass-energy equivalence, a principle stating that mass and energy are the same physical entity and can be changed into each other.
This principle is most notably demonstrated by the equation E=mc^2, formulated by Albert Einstein.
As nuclear reactions involve changes in the nuclear structure of atoms, they typically release far greater amounts of energy than chemical reactions.

Nuclear fission is used in nuclear power plants to generate electricity, and in the production of nuclear weapons.
Nuclear fusion powers our Sun and other stars, and is being attempted for power generation on Earth due to its potential as a clean and virtually limitless source of power.
Radioactive decay is used in applications such as radioactive dating, medical imaging and treatment, and in smoke detectors.