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  2. Cell theory - Wikipedia

    en.wikipedia.org/wiki/Cell_theory

    From these conclusions about plants and animals, two of the three tenets of cell theory were postulated. 1. All living organisms are composed of one or more cells 2. The cell is the most basic unit of life. Schleiden's theory of free cell formation through crystallization was refuted in the 1850s by Robert Remak, Rudolf Virchow, and Albert ...

  3. Law of multiple proportions - Wikipedia

    en.wikipedia.org/wiki/Law_of_multiple_proportions

    The other is a white powder which Dalton referred to as "the deutoxide of tin", which is 78.7% tin and 21.3% oxygen. Adjusting these figures, in the grey powder there is about 13.5 g of oxygen for every 100 g of tin, and in the white powder there is about 27 g of oxygen for every 100 g of tin. 13.5 and 27 form a ratio of 1:2.

  4. John Dalton - Wikipedia

    en.wikipedia.org/wiki/John_Dalton

    John Dalton FRS (/ ˈ d ɔː l t ən /; 5 or 6 September 1766 – 27 July 1844) was an English chemist, physicist and meteorologist. [1] He introduced the atomic theory into chemistry. He also researched colour blindness ; as a result, the umbrella term for red-green congenital colour blindness disorders is Daltonism in several languages.

  5. Gas - Wikipedia

    en.wikipedia.org/wiki/Gas

    Drifting smoke particles indicate the movement of the surrounding gas.. Gas is one of the four fundamental states of matter.The others are solid, liquid, and plasma. [1] A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or compound molecules made from a variety of atoms (e.g. carbon dioxide).

  6. 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.

  7. History of atomic theory - Wikipedia

    en.wikipedia.org/wiki/History_of_atomic_theory

    In 1804, Dalton explained his atomic theory to his friend and fellow chemist Thomas Thomson, who published an explanation of Dalton's theory in his book A System of Chemistry in 1807. According to Thomson, Dalton's idea first occurred to him when experimenting with "olefiant gas" and "carburetted hydrogen gas" .

  8. Preformationism - Wikipedia

    en.wikipedia.org/wiki/Preformationism

    When John Dalton's atomic theory of matter superseded Descartes' philosophy of infinite divisibility at the beginning of the 19th century, preformationism was struck a further blow. There was not enough space at the bottom of the spectrum to accommodate infinitely stacked animalcules, without bumping into the constituent parts of matter.

  9. Free-radical theory of aging - Wikipedia

    en.wikipedia.org/wiki/Free-radical_theory_of_aging

    Brewer proposed a theory which integrates the free radical theory of aging with the insulin signalling effects in aging. [36] Brewer's theory suggests "sedentary behaviour associated with age triggers an oxidized redox shift and impaired mitochondrial function". [36] This mitochondrial impairment leads to more sedentary behaviour and ...