radiation all around us
- visible light and infrared radiation are electromagnetic radiation from sun
- microwaves and radio waves are radiation used in communication systems.
- they are non ionising radiation. they have little biological effects
Definition
Ionising radiation is radiation with high energies that can knock off electrons from atoms to form ions #PhysicsDefinitions
very high frequency UV rays, X rays, gamma rays → e.g. of ionising electromagnetic radiation highly energetic particles from cosmic rays and from naturally occuring radioactive materials are examples of ionising nuclear radiation
Definition
Background radiation refers to nuclear radiation in an env. where no radioactive source has been deliberately introduced #PhysicsDefinitions
we encounter background radiation every day. sources of background radiation can be artificial (man made) or natural
| Artificial Sources | Natural Sources |
|---|---|
| medical x rays | rocks |
| building materials | radon gas in air |
| waste products from nuclear power stations | food and drink (e.g food high in potassium like bananas, carrots, and salts may contain radioactive potassium-40) |
natural background radiation → accounts for 80% of radiation we are exposed to amt of background radiation we encounter is usually well below recommended limit of radiation exposure