Alpha, Beta and Gamma Radiation Decay

240px-Alpha_Decay.svg[1].pngAlpha decay (radioactive decay): Occurs when the nucleus has too many protons in it and it wants to rid of them through excessive repulsion. This causes an alpha or helium particle to be released in order to stop the repulsion. With the particle leaving the nucleus it causes the element to decay or change. It causes the mass number to be four less and the atomic number two less than the element before, this causes a transmutation. α, is the symbol for alpha. The equation using an example of uranium is represented by:


Uranium is represented as the parent atom and Thorium is represented as the daughter atom.

240px-Beta-minus_Decay.svg[1].pngBeta decay (radioactive decay): occurs when a beta particle is emitted out of an atom. A beta particle is the same as an electron or a positron (positive electron). There are two types of beta decay, positive and negative. When a beta decay is positive (β+), it is emitting a positive electron, also known as a positron, when this is occurring it is accompanied by a neutrino. When a beta decay is negative (β−), it is emitting a normal electron, when this is occurring it is accompanied by an anti-neutrino. The neutrinos and antineutrinos do not have any neutrons or protons; they are simply there to make up for the energy “lost” through decay. When the decay occurs the mass number and stays the same and the atomic number increases or decreases by one, this causes a transmutation.


In this equation above the beta particle can be either negative or positive and is accompanied with extra energy to create balance, which is the neutrino or anti-neutrino.

250px-Gamma_Decay.svg[1].pngGamma Decay (radioactive decay): Occurs when a gamma ray is emitted, a high energy photon is emitted by the nucleus, this does not result in transmutation. Here is an example of an equation:


With gamma decay it causes the element to remain the same just with gamma added to it. Although gamma does not cause a transmutation, when you add an alpha or beta particle with a gamma it causes a transmutation.

By: Heather Massicotte