https://padlet.com/weiruiman/rxxqt6r6qzyo A brief timeline of scientists and their contribution to the chemical world. en-us 2018-10-08 13:09:54 UTC 2026-01-24 05:09:57 UTC hello@padlet.com weiruiman https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/290280691 In 400 B.C. Greece, Democritus came up with the theory that all matter is made up of small particles called atoms. Each different material had a different shape of what he called atomos. They were circular in shape. ]]> 2018-10-08 13:16:38 UTC https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/290280691 weiruiman https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/290281560 In 1803 U.K., Dalton added onto Democritus's theory. He also stated that compounds were arrangements of small particles in a fixed ratio. He also proposed that chemical reactions resulted in the rearrangement of particles. ]]> 2018-10-08 13:18:07 UTC https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/290281560 weiruiman https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/290288035 In 1911, Russia, Mendeleev drafted the first periodic table]]> 2018-10-08 13:30:13 UTC https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/290288035 weiruiman https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/290291119 In 1897, UK, Thomson discovered subatomic particles (electrons and the nucleus). ]]> 2018-10-08 13:36:25 UTC https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/290291119 weiruiman https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/290294049 In 1911, U.K., Rutherford was the first to discover that atoms had a largely empty space in between the nucleus and electrons.]]> 2018-10-08 13:42:03 UTC https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/290294049 weiruiman https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/290295657 In 1913 Denmark, Bohr discovered that atoms had orbitals hat electrons traveled in and that the electrons in the outer shell determined the properties of an element. ]]> 2018-10-08 13:45:26 UTC https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/290295657 weiruiman https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/291545431 In 1936 Austria, Schrodinger added onto the Bohr model. He used mathematical equations to find the likelihood to find an electron in a certain position (Quantum Mechanical Model).]]> 2018-10-11 03:23:08 UTC https://padlet.com/weiruiman/rxxqt6r6qzyo/wish/291545431