Alpha particles
Alpha particles also called alpha radiation or alpha rays, consist of two protons
and two neutrons bound together in to a particle identical to a helium - 4 nucleus.
they are emitted from nucleus of some radionuclides during a form of radioactive
decay called alpha decay.
Alpha particles discovered and named by Ernest Rutherford [1899]. It was the first
type of nuclear radiation to be discovered, before beta particles and gamma rays.
Alpha ions written as He2+ because it indicating a helium ion with a +2 charge,
when the ion gains two electrons from its surrounding, the alpha particles
become a normal helium atom.
Properties of alpha particles
Alpha particles are relatively heavy and slow compared with other particles, so
they pose little danger to humans unless ingested.
Alpha particles are highly ionizing, are unable to penetrate very far through matter
and, are bought to rest by a few centimeters of air or less then a tenth of a
millimeter of biological tissue. they cannot penetrate humans epidermis or outer
layer of skin.
