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  2. History of atomic theory - Wikipedia

    en.wikipedia.org/wiki/History_of_atomic_theory

    This meant that "compound atoms" such as carbon dioxide could be divided, as opposed to "elementary atoms". Dalton disliked the word "molecule", regarding it as "diminutive". [ 4 ] [ 24 ] Amedeo Avogadro did the opposite: he exclusively used the word "molecule" in his writings, eschewing the word "atom", instead using the term "elementary ...

  3. Atomism - Wikipedia

    en.wikipedia.org/wiki/Atomism

    1st. That water is a binary compound of hydrogen and oxygen, and the relative weights of the two elementary atoms are as 1:7, nearly; 2nd. That ammonia is a binary compound of hydrogen and azote nitrogen, and the relative weights of the two atoms are as 1:5, nearly...

  4. History of chemistry - Wikipedia

    en.wikipedia.org/wiki/History_of_chemistry

    Many reasons for this neglect have been cited, including some theoretical problems, such as Jöns Jacob Berzelius's "dualism", which asserted that compounds are held together by the attraction of positive and negative electrical charges, making it inconceivable that a molecule composed of two electrically similar atoms—as in oxygen—could exist.

  5. Leucippus - Wikipedia

    en.wikipedia.org/wiki/Leucippus

    Leucippus said that the cosmos was created when a large group of atoms came together and swirled as a vortex. They shifted around each other until they were sorted "like to like". The larger atoms gathered in the center while the smaller ones were pushed to the edge. The smaller atoms became the celestial bodies of the cosmos.

  6. History of molecular theory - Wikipedia

    en.wikipedia.org/wiki/History_of_molecular_theory

    Specifically, he uses the name "elementary molecule" when referring to atoms and to complicate the matter also speaks of "compound molecules" and "composite molecules". During his stay in Vercelli, Avogadro wrote a concise note ( memoria ) in which he declared the hypothesis of what we now call Avogadro's law : equal volumes of gases, at the ...

  7. Democritus - Wikipedia

    en.wikipedia.org/wiki/Democritus

    Democritus (/ d ɪ ˈ m ɒ k r ɪ t ə s /, dim-OCK-rit-əs; Greek: Δημόκριτος, Dēmókritos, meaning "chosen of the people"; c. 460 – c. 370 BC) was an Ancient Greek pre-Socratic philosopher from Abdera, primarily remembered today for his formulation of an atomic theory of the universe. [2]

  8. Chemical element - Wikipedia

    en.wikipedia.org/wiki/Chemical_element

    For example, molecules of water (H 2 O) contain atoms of hydrogen (H) and oxygen (O), so water can be said as a compound consisting of the elements hydrogen (H) and oxygen (O) even though it does not contain the chemical substances (di)hydrogen (H 2) and (di)oxygen (O 2), as H 2 O molecules are different from H 2 and O 2 molecules. For the ...

  9. Discovery of chemical elements - Wikipedia

    en.wikipedia.org/wiki/Discovery_of_chemical_elements

    Lavoisier writes the first modern list of chemical elements – containing 33 elements including light and heat but omitting Na, K (he was unsure of whether soda and potash without carbonic acid, i.e. Na 2 O and K 2 O, are simple substances or compounds like NH 3), [91] Sr, Te; some elements were listed in the table as unextracted "radicals ...