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Undo revision 496359 by [[Special:Contributions/Jinxmchue|Jinxmchue]] ([[User talk:Jinxmchue|Talk]]) Entry was relevant, especially on the talk page
: Radiation can be divided into two types - ionizing and non-ionizing. The distinction is how they interact with matter. Non-ionizing radiation are things like microwaves, radio waves, viable light. Ionizing radiation are subatomic particles and high energy photons. This type of radiation can knock off an electron from an atom or molecule leaving an ion. Xrays and even ultraviolet can be ionizing, but they are not produced by a radioactive substance.
: A substance that is radioactive (a radionuclide) emits ionizing radiation naturally. Uranium, radium, radon, carbon-14, etc... For fun, carbon-11, nitrogen-13, oxygen-15 , and fluorine-18 are the radionuclides used in PET scans - radioactive substances are sometimes more familiar elements than the classic big heavy atoms. The distinction is that a substance used to produce x-rays in an x-ray tube is not naturally producing it. Not all ionizing radiation is from a radioactive substance. Gama rays, for example can be formed with supernova. Xrays are given off in the jets from a black hole as electrons are wiped around magnetic fields. --[[User:Rutm|Rutm]] 18:50, 8 July 2008 (EDT)
== McGraw-Hill definition -- radioactivity vs. radiation ==
The McGraw-Hill Children's Dictionary (ISBN 1-57768-298-X) is a resource that I would judge to be aimed at 10-year-olds, at least 6 years younger than what I think CP's target audience should be. The blurb on the back cover indicates a target audience of "elementary school through middle school". I believe that means 8- to 13-year-olds.
Their entry for radioactivity is:
:The giving off of energy as a result of the decay of unstable atoms.
::''Uranium has a high level of radioactivity.''
Their entry for radiation is:
:The waves of energy sent out by sources of heat or light, or by a radioactive material.
::''She wore a hat to protect her skin from the radiation of the sun.''
::''Many people are concerned about radiation from nuclear waste.''
