Editing History of atomic theory (section)

==Philosophical atomism==
{{main|Atomism}}
{{see also|Alchemy}}
The basic idea that matter is made up of tiny indivisible particles is an old idea that appeared in many ancient cultures. The word ''atom'' is derived from the [[ancient Greek]] word ''atomos'',{{efn|a combination of the negative term "a-" and "τομή," the term for "cut"}} which means "uncuttable". This ancient idea was based in philosophical reasoning rather than scientific reasoning. Modern atomic theory is not based on these old concepts.<ref name=Pullman-1998>{{cite book|last1=Pullman|first1=Bernard|title=The Atom in the History of Human Thought|date=1998|publisher=Oxford University Press|location=Oxford, England|isbn=978-0-19-515040-7|pages=31–33|url=https://books.google.com/books?id=IQs5hur-BpgC&q=Leucippus+Democritus+atom&pg=PA56|access-date=25 October 2020|archive-date=5 February 2021|archive-url=https://web.archive.org/web/20210205165029/https://books.google.com/books?id=IQs5hur-BpgC&q=Leucippus+Democritus+atom&pg=PA56|url-status=live}}</ref><ref>[[#refMelsen1952|Melsen (1952). ''From Atomos to Atom'', pp. 18–19]]</ref> In the early 19th century, the scientist [[John Dalton]] noticed that [[chemical substance]]s seemed to combine with each other by discrete and consistent units of weight, and he decided to use the word ''atom'' to refer to these units.<ref name="Pullman 1998 p. 201">[[#refPullman1998|Pullman (1998). ''The Atom in the History of Human Thought'', p. 201]]</ref>