IB+MYP+Radioactivity

Nuclear Physics/Radioactivity
The discovery of Radioactivity media type="custom" key="20537178"

Radioactivity:
The emission of **radiation** by unstable atomic nuclei undergoing **radioactive decay**.

Radiation:

 * a.** Emission and propagation and emission of energy in the form of rays or waves.
 * b.** Energy radiated or transmitted as rays, waves, in the form of particles.
 * c.** A stream of particles or electromagnetic waves emitted by the atoms and molecules of a radioactive substance as a result of nuclear decay.

Different level of background radiation Listen to different level of natural radioactivity

Natural Radioactivity in soil from http://www.nucleonica.net The table below summarises the amount of radioactivity in soil (in Bq/kg) and the total amount of radioactivity in a volume of soil 1 square mile in area and 1 foot deep. The total volume of soil is approximately 8 x 105 m3. Although the activity levels depend on the soil type etc., the table gives typical values for a soil density of 1.6 g/cm3).

Reference: Idaho State University, [| http://www.physics.isu.edu/radinf/natural.htm]
 * ** Natural Radioactivity by the Square Mile, 1 Foot Deep ** ||
 * ** Nuclide ** || ** Activity used in calculation ** || ** Mass of Nuclide ** || ** Activity found in the volume of soil ** ||
 * ** Uranium ** || 25 Bq/kg || 2,200 kg || 31 GBq ||
 * ** Thorium ** || 40 Bq/kg || 12,000 kg || 52 GBq ||
 * ** Potassium 40 ** || 400 Bq/kg || 2000 kg || 500 GBq ||
 * ** Radium ** || 48 Bq/kg || 1.7 g || 63 GBq ||
 * ** Radon ** || 10 kBq/m³ || 11 µg || 7.4 GBq ||
 * || ** Total: ** || >653 GBq ||



DECAY: Spontaneous disintegration of a nucleus accompanied by the emission of ionising radiation in the form of alpha or beta particles or gamma rays. Radioactive decay from BBC Bitesize Alpha particles media type="custom" key="11786526" width="50" height="50" Beta particles media type="custom" key="11786518" width="50" height="50" Gamma radiation

IONISATION: The formation of ions by separating atoms or by adding or subtracting electrons from atoms as a result of particle collisions, or radiation.

Radioactive Decay, Fission and Chain Reactions


Nuclear fission media type="custom" key="11786580" width="50" height="50"

Half Life:
Carbon dating

**The randomness of radioactive decay**
It is impossible to predict when the next decay will happen as radioactive decay is a random process. In a sample of a radioactive material, you cannot predict when the next atom will decay. Atoms decay randomly over time. It is also impossible to point at an individual atom saying it will be the next one to decay. Radioactive decay occurs randomly over space and time.
 * [[image:IMG_1192.jpg width="388" height="505"]] || [[image:IMG_1197.jpg width="400" height="531"]] ||



Controlling the thickness of paper

Revision from BBC Bitesize For your revision, also try out the questions by clicking revise here and on iLearn