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Memoir of John Dalton and History of the Atomic Theory. London: H. Bailliere. ISBN 978-1-4021-6437-8; Smyth, A. L. (1998). John Dalton, 1766–1844: A Bibliography of Works by and About Him, With an Annotated List of His Surviving Apparatus and Personal Effects. Manchester Literary and Philosophical Publications.
1914 James Franck and Gustav Hertz observe atomic excitation; 1915 Arnold Sommerfeld develops a modified Bohr atomic model with elliptic orbits to explain relativistic fine structure; 1916 Gilbert N. Lewis and Irving Langmuir formulate an electron shell model of chemical bonding; 1917 Albert Einstein introduces the idea of stimulated radiation ...
This led to a series of atomic models with some quantum aspects, such as that of Arthur Erich Haas in 1910 [37]: 197 and the 1912 John William Nicholson atomic model with quantized angular momentum as h/2 π. [58] [59] The dynamical structure of these models was still classical, but in 1913, Bohr abandon the classical approach.
2650 BC: The oldest extant record of a unit of length, the cubit-rod ruler, is from Nippur. 2600 BC: The oldest attested evidence for the existence of units of weight, and weighing scales date to the Fourth Dynasty of Egypt, with Deben (unit) balance weights, excavated from the reign of Sneferu, though earlier usage has been proposed. [4]
John Dalton's model of the atom, which held that atoms are indivisible and indestructible (superseded by nuclear physics) and that all atoms of a given element are identical in mass (superseded by discovery of atomic isotopes). [13] Plum pudding model of the atom—assuming the protons and electrons were mixed together in a single mass
1803 – John Dalton: Atomic theory of matter [citation needed] 1806 – Thomas Young: Kinetic energy; 1814 – Augustin-Jean Fresnel: Wave theory of light, optical interference; 1820 – André-Marie Ampère, Jean-Baptiste Biot, and Félix Savart: Evidence for electromagnetic interactions (Biot–Savart law) 1822 – Joseph Fourier: Heat equation
An image from John Dalton's A New System of Chemical Philosophy, the first modern explanation of atomic theory.. This timeline of chemistry lists important works, discoveries, ideas, inventions, and experiments that significantly changed humanity's understanding of the modern science known as chemistry, defined as the scientific study of the composition of matter and of its interactions.
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 ...