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Period: 100 to
atomic models
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426
plato
in his circa 360BC dialogue Timaeus, supposedly following Pythagoras, introduced the atomic theory proposition that ideal geometric forms serve as atoms, according to which atoms broke down mathematically into triangles -
460
Democritus
Student of Leucippus, who furthered the atomic view, whose famous motto is: "nothing exists but atoms and voids." Another version reads: "no thing is real but atoms in a void, and all things happen by chance and necessity." -
robert boyle
Born in Ireland on 25 January, 1627 to a wealthy and influential family, Robert Boyle’s father, Richard Boyle, was Lord Treasurer of the Kingdom of Ireland. Boyle received the best education from various prestigious schools, including Eton, where he studied philosophy, religion, mathematics and the latest trends in physics and chemistry. -
lavoistier
. Lavoisier found that mass is conserved in a chemical reaction. The total mass of the products of a chemical reaction is always the same as the total mass of the starting materials consumed in the reaction. His results led to one of the fundamental laws of chemical behavior: the law of conservation of matter, which states that matter is conserved in a chemical reaction. -
John Dalton
Using the hooked atom theory as a model for bonding, founded modern 'atomic theory' by initiating the basics of stoichiometry, assigning the hydrogen atom, the lightest element, as unity, and determined the atomic ratios in various molecules, such as nitrous anhydride N2O3. -
j.j. Thomson
Thomson interpreted the deflection of the rays by electrically charged plates and magnets as evidence of “bodies much smaller than atoms” that he calculated as having a very large value for the charge-to-mass ratio. Later he estimated the value of the charge itself. -
Ernest rutherford
After experimentally discovering the nucleus, in his 1909 gold foil experiment, conceived of the 'Rutherford model' of the atom in 1911, according to which the atom had most of its mass at the center characterized by a "positive central charge N e, and surrounded by a compensating charge of N electrons"; Rutherford failed to speculate further on electronic structure, but did mention the Saturn ring model of Nagaoka; Rutherford later coined the term 'proton' (1919) for structure of hydrogen nucle -
neils bohr
Born in Copenhagen in 1885 to well-educated parents, Bohr became interested in physics at a young age. He studied the subject throughout his undergraduate and graduate years and earned a doctorate in physics in 1911 from Copenhagen University.