Spectrum
IRON SPECTRUM
https://pediaa.com/difference-between-continuous-spectrum-and-line-spectrum/
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Emission and absorption lines
https://physics.ucr.edu/~wudka/Physics7/Notes_www/node107.html
Hydrogen Spectrum
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https://www.buzzle.com/articles/emission-spectrum-vs-absorption-spectrum.html
https://www.consumerreports.org/cro/news/2015/02/can-mammograms-cause-cancer/index.htm
https://www.greenmedinfo.com/blog/how-x-ray-mammography-accelerating-epidemic-cancer