Image: Jacques-Louis David - Metropolitan Museum of Art


Image: public domain


Image: public domain


Image: http://www.sen20.com


Image: ovovideo.com


Image: Date and photographer unknown; courtesy of University Archives, KU Leuven, Archive Walter and Ida Noddack-Tacke, nr. 51.


Image: Royal Society of Chemistry


Image: public domain


Image: public domain


Image: Royal Society of Chemistry


Image: public domain


Image: MICHAEL BRANSOM, AMERICAN CHEMICAL SOCIETY

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