1.0 link Rainbow Dash Network http://rainbowdash.net/ aaaaaaaaaa (aaaaaaaaa) http://rainbowdash.net/aaaaaaaaa http://rainbowdash.net/notice/124587 @<span class="vcard"><a href="http://rainbowdash.net/user/218" class="url" title="Brendan"><span class="fn nickname">abigpony</span></a></span> So basically, these electrons that you blast out with x-ray radiation will actually become wavelike (recall the whole particle/wave duality thing), and will bounce off neighbouring atoms and cause interference patterns that we can measure. It turns out that these specific patterns and whatnot are element-specific. So, for example, if you shoot an x-ray of, say, 11.8 keV of energy into something, and you get a signal response, you know that it's a particular element (for this example, 11.8 is Arsenic)