When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. History of atomic theory - Wikipedia

    en.wikipedia.org/wiki/History_of_atomic_theory

    Dalton thought that water was a "binary compound", i.e. one hydrogen atom and one oxygen atom. Dalton did not know that in their natural gaseous state, the ultimate particles of oxygen, nitrogen, and hydrogen exist in pairs (O 2, N 2, and H 2). Nor was he aware of valencies. These properties of atoms were discovered later in the 19th century.

  3. 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.

  4. Dalton's law - Wikipedia

    en.wikipedia.org/wiki/Dalton's_law

    Dalton's law (also called Dalton's law of partial pressures) states that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases. [1] This empirical law was observed by John Dalton in 1801 and published in 1802. [2] Dalton's law is related to the ideal gas laws.

  5. Law of multiple proportions - Wikipedia

    en.wikipedia.org/wiki/Law_of_multiple_proportions

    But in other cases, he got their formulas right. The following examples come from Dalton's own books A New System of Chemical Philosophy (in two volumes, 1808 and 1817): Example 1 — tin oxides: Dalton identified two types of tin oxide. One is a grey powder that Dalton referred to as "the protoxide of tin", which is 88.1% tin and 11.9% oxygen ...

  6. History of subatomic physics - Wikipedia

    en.wikipedia.org/wiki/History_of_subatomic_physics

    In the 19th century, John Dalton, through his work on stoichiometry, concluded that each chemical element was composed of a single, unique type of particle. Dalton and his contemporaries believed those were the fundamental particles of nature and thus named them atoms, after the Greek word atomos, meaning "indivisible" [3] or "uncut". However ...

  7. Conservation of mass - Wikipedia

    en.wikipedia.org/wiki/Conservation_of_mass

    Such is the case when any energy or matter is allowed into, or out of, the system. However, unless radioactivity or nuclear reactions are involved, the amount of energy entering or escaping such systems (as heat, mechanical work, or electromagnetic radiation) is usually too small to be measured as a change in the mass of the system.

  8. 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 ...

  9. Timeline of physical chemistry - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_physical_chemistry

    Determined the equivalence of matter and energy. 1905: Albert Einstein: First to explain the effects of Brownian motion as caused by the kinetic energy (i.e., movement) of atoms, which was subsequently, experimentally verified by Jean Baptiste Perrin, thereby settling the century-long dispute about the validity of John Dalton's atomic theory. 1905