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  2. John Dalton - Wikipedia

    en.wikipedia.org/wiki/John_Dalton

    Various atoms and molecules as depicted in John Dalton's A New System of Chemical Philosophy (1808) Dalton published his first table of relative atomic weights containing six elements (hydrogen, oxygen, nitrogen, carbon, sulfur and phosphorus), relative to the weight of an atom of hydrogen conventionally taken as 1. [ 18 ]

  3. Law of multiple proportions - Wikipedia

    en.wikipedia.org/wiki/Law_of_multiple_proportions

    In reality, an ethylene molecule has two carbon atoms and four hydrogen atoms (C 2 H 4), and a methane molecule has one carbon atom and four hydrogen atoms (CH 4). In this particular case, Dalton was mistaken about the formulas of these compounds, and it wasn't his only mistake. But in other cases, he got their formulas right.

  4. 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 molecule ...

  5. Law of definite proportions - Wikipedia

    en.wikipedia.org/wiki/Law_of_definite_proportions

    The law of definite proportions contributed to the atomic theory that John Dalton promoted beginning in 1805, which explained matter as consisting of discrete atoms, that there was one type of atom for each element, and that the compounds were made of combinations of different types of atoms in fixed proportions. [5]

  6. History of molecular theory - Wikipedia

    en.wikipedia.org/wiki/History_of_molecular_theory

    John Dalton's union of atoms combined in ratios (1808) Similar to these views, in 1803 John Dalton took the atomic weight of hydrogen, the lightest element, as unity, and determined, for example, that the ratio for nitrous anhydride was 2 to 3 which gives the formula N 2 O 3. Dalton incorrectly imagined that atoms "hooked" together to form ...

  7. Atomism - Wikipedia

    en.wikipedia.org/wiki/Atomism

    John Dalton's alternative formulae for water and ammonia. And then he proceeded to give a list of relative weights in the compositions of several common compounds, summarizing: [73] 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.

  8. History of the periodic table - Wikipedia

    en.wikipedia.org/wiki/History_of_the_periodic_table

    Dalton's 1806 list of known elements by atomic weight. In 1808–10, British natural philosopher John Dalton published a method by which to arrive at provisional atomic weights for the elements known in his day, from stoichiometric measurements and reasonable inferences. Dalton's atomic theory was adopted by many chemists during the 1810s and ...

  9. History of chemistry - Wikipedia

    en.wikipedia.org/wiki/History_of_chemistry

    Dalton also proposed a modern atomic theory in 1803 which stated that all matter was composed of small indivisible particles termed atoms, atoms of a given element possess unique characteristics and weight, and three types of atoms exist: simple (elements), compound (simple molecules), and complex (complex molecules).