ip2.28.3 simple introduction to decay simple introduction to decay
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IP2.28.3 Simple introduction to decay
Simple introduction to decay
IP2.28.3 Simple introduction to decay
Some atomic nuclei are unstable and they undergo a process of radioactive decay. In this process the nucleus loses energy and emits some ionising particles or radiation.
The nucleus is then in a lower and more stable state.
IP2.28.3 Simple introduction to decay
There are three different type of ionising particle or radiation. They were named alphabetically (using the Greek alphabet):
Alpha particles (α) Beta particles (β) Gamma radiation (γ)
IP2.28.3 Simple introduction to decay
The size, charge and nature of each type of radiation are: Alpha particles (α) – 2 protons and 2 neutrons
+ve charge Beta particles (β) – high speed electron
–ve charge Gamma radiation (γ) – high energy
electromagnetic wave – no charge.
IP2.28.3 Simple introduction to decay
Why does radioactive decay occur? Some atoms are unstable – with a slight rearrangement
of the particles in the atom it would be able to release some energy and exist in a lower energy state.
In radioactive decay this process is spontaneous. It does not need anything to trigger it to occur – it just happens.
Think of it like an avalanche. Snow builds up on a mountain side and everything looks okay, until an avalanche occurs. The snow was in an unstable state. The avalanche releases a large amount of energy and the snow ends up at the bottom of the mountain in a much lower energy state.