Radioactivity

Radioactivity

1. Atoms consist of a nucleus plus orbiting electrons

   • The Nuclues of an atom contains protons and neutrons it makes up most of the atom but it takes up virtually no space. The electrons are really really small. They whizz around the outside of the atom in shells. These shells take up a lot of space giving the atom its overall size

2. The Number of Neutrons in an Element isnt Fixed

   • The proton number is specific to an element but the amount of neutrons is not fixed. If an atom has the same number of protons but a different number of neutrons they are called isotpes. Some isotopes are unstable - meaning the nucleus breaks down and emits radiation.

3. Radioactive Elements Emit Ionising Radiation

   • Some elements emit ionising radiation all the time - these elements are radioactive. Radioactive atoms are unstable - they decay. Unstable atoms decay at random and you can not predict when it will happen (its unaffected by physical temperature). When an atom does decay it spits our one or more of three types of ionising radiation (alpha, beta or gamma). In the process the atom changes into a new element. Ionising radiation can transfer enough energy to break an atom or molecule into ions. These ions can then go on to take part in other chemical reactions