Radioactivity 2

Ionising Radiation

Ionising radiation causes neutral atoms to become ions by making them gain or lose electrical charge.  Ionising radiation is the form of alpha or beta particles or electromagnetic waves like gamma rays.  The range is the distance travelled by the radiation, before all its energy is absorbed.

Decay Equations

       Am -------------->                +        Np

        Sr --------------->                +        Y

       Co -------------->           +          Co

Measuring Radiation

Radiation is measured in a unit called Becquerels (Bq).  An activity of 1Bq means that one nucleus is decaying each second.  The average radiation for one minute is:

24+22+14/3 = 60/3 = 20 counts per minute

This means that the background count in the room is 20/60 = 1/3 counts per second.  The background is 0.33Bq.

Sources of Radiation

Radiation comes from two types of sources, naturally occurring and artificial.

Natural: rocks, air(radon gas), food and drink, cosmic rays.

Artificial: Nuclear power stations, nuclear weapons, medical uses.

Background Radiation

• radon gas: 50%
• ground…