The thorium-234 produced above experiences two successive beta decays: Gamma rays have very great penetrating power and are not affected at all by a magnetic field.
They move at the speed of light and have a very short wavelength (or high frequency); thus they are a type of electromagnetic radiation (see gamma radiationgamma radiation,high-energy photons emitted as one of the three types of radiation resulting from natural radioactivity.
Alpha rays have the least penetrating power, move at a slower velocity than the other types, and are deflected slightly by a magnetic field in a direction that indicates a positive charge.
The radiation produced during radioactivity is predominantly of three types, designated as alpha, beta, and gamma rays.
These types differ in velocity, in the way in which they are affected by a magnetic field, and in their ability to penetrate or pass through matter.
Depending on the element, a half-life can be as short as a fraction of a second or as long as several billion years.
The product of a radioactive decay may itself be unstable and undergo further decays, by either alpha or beta emission.