All material is composed of atoms. Atoms are comprised of various particles, which include the nucleus.
- The nucleus contains particles called protons and neutrons, and the outer shell is made up of other particles called electrons.
- The nucleus maintains a positive electrical charge, while the electrons have a negative electrical charge.
- The forces within the nucleus work toward maintaining a stable balance between the positive charge of the protons and the negative charge of the electrons.
- The process by which the nuclei of atoms work toward becoming stable is to get rid of excess energy.
- Unstable nuclei may emit a quantity of energy, or they may emit a particle.
- This emitted atomic energy and/or particle is what is commonly called radiation.
There are two basic types of radiation: One type of radiation is tiny fast-moving particles that have both energy and mass, which is known as particle radiation. The other kind is pure energy with no weight. This radiation type is comprised of vibrating or pulsating waves of electrical and magnetic energy.
Ionization is the process of removing electrons from atoms, leaving behind two electrically charged particles (ions). Some forms of radiation like visible light, microwaves, or radio waves do not have sufficient energy to remove electrons from atoms and hence referred to as non-ionizing radiation. Ionizing radiation causes changes in living tissue.
When large atoms become unstable they emit radiation energy to become stable again. This process is called radioactive decay. This radiation can be emitted in the form of a positively charged alpha particle, a negatively charged Beta particle, or Gamma and X-rays.
The biological effects of radiation on living cells may result in three outcomes: Cells die and are removed thru normal biological processes Cells incorrectly repair themselves resulting in biophysical mutation and replication, creating free radicals which result in diseases such as cancer. In some instances, injured or damaged cells are able to repair themselves, resulting in little residual damage
There are 3 main ways to reduce a person’s amount of radiation absorption. Time -limiting or minimizing exposure time will reduce the dose received from the source of the radiation. Distance – The intensity of the radiation will decrease the further one is from the source. Shielding – creating a barrier between the radiating source and the individual will help to protect from the harmful effects.
Half-life is a constant; all atoms of the same element have the same half-life just as they have the same “mean” life. The half-life of a nuclide is the time it takes for half of the original number of atoms to decay. This constant rate of decay varies depending upon the particular element involved.
The fission interaction is the basis of all nuclear chain reactions, without it there would be no nuclear reaction. In fission, the neutron bombards an atom of fissionable material splitting it apart and producing additional free neutrons to perpetuate the reaction, as well as heat energy and radiation energy. A fissionable element will have a heavy nucleus from which an average of two or three neutrons are emitted when it is struck by a neutron.