Radioactivity (with or without the resources) http://tiny.cc/EMSrad
The terms ‘radiation’ and ‘radioactivity’ are often interchangeable in the public mind. Because of its invisibility, radiation is commonly feared.
True or false
1.Radioactive substances make everything near to them radioactive.
2.Once something has become radioactive, there is nothing you can do about it.
3.Some radioactive substances are more dangerous than others.
4.Radioactive means giving off radio-waves.
5.Saying that a radioactive substance has a half life of three days means any produced now will all be gone in six days
In April 1986, a serious accident occurred at the nuclear power station at Chernobyl in Russia. A week later, radiation detectors (Geiger counters) in Britain recorded higher than usual levels of radiation. Britain is more than 1000 miles from Chernobyl!
Explain what reached the Geiger counters in Britain to make them record extra counts.
•Many students confuse ‘radiation’ and ‘radioactive material’.
•After the Chernobyl accident, many newspaper articles referred to a “cloud of radiation” and drinking water contaminated with “radiation”.
Many students appear to interpret the idea that “radiation is absorbed” differently from the scientific interpretation. They believe that objects that have been irradiated will themselves become radioactive – that they can re-emit the radiation some time later.
The underlying idea here is that they seem to think that radiation is somehow “conserved”.
•An inability to distinguish between the ideas of irradiation and contamination
•An inability to interpret the ideas of activity and dose
What is “radioactive”
The Radiation Protection Division of the Health Protection Agency defines a radioactive substance as having a specific activity ³ 400 Bq/kg.
•1841- Eugene Peligot discovers uranium
•1895 – William Roentgen discovers X-rays
•1896 – Henri Becquerel discovers that rocks that contain uranium emit radiation
•1988/9 – Marie Curie discovers radium, polonium and thorium
•1903 – Becquerel, and the Curies get Nobel Prize
Story: Why green?