What is radioactivity and ionising radiation?
Radioactivity involves the smallest building blocks of a substance, i.e. atoms. Most atoms are stable but in some the balance in the nucleus is disrupted by an excess of neutrons or protons. In that case the nucleus has too much energy, which means that it is unstable or radioactive. Unstable nuclei release their excess energy via ionising radiation. This process – radioactive decay – continues until the nuclei reach a balance.
When the energy released during this process passes through another substance, the rays collide with other atoms or molecules. As a result the other atoms or molecules become electrically charged and turn into ions. This is referred to as ionisation. We consequently use the term ionising radiation, which can have an adverse impact on humans, animals, plants, bacteria, etc.
More info: Protection of man and the environment
More info: Health