https://padlet.com/491614/rwbraraohhg1 the history of atoms en-us 2016-11-09 18:19:47 UTC 2016-12-11 20:57:46 UTC hello@padlet.com 491614 https://padlet.com/491614/rwbraraohhg1/wish/136511787 Dalton believed that all matter is made of atoms and that atoms are indivisible and indestructible ]]> 2016-11-09 18:21:29 UTC https://padlet.com/491614/rwbraraohhg1/wish/136511787 491614 https://padlet.com/491614/rwbraraohhg1/wish/143016464 Studied radiations emitted from uranium and thorium and named them alpha and  beta. ]]> 2016-12-11 20:49:43 UTC https://padlet.com/491614/rwbraraohhg1/wish/143016464 491614 https://padlet.com/491614/rwbraraohhg1/wish/143017291  Used a CRT to experimentally determine the charge to mass ratio (e/m) of an electron =1.759 x 10 8 coulombs/gram.  Studied "canal rays" and found they were associated with the proton H + . ]]> 2016-12-11 20:52:49 UTC https://padlet.com/491614/rwbraraohhg1/wish/143017291 491614 https://padlet.com/491614/rwbraraohhg1/wish/143017358  Developed an explanation of  atomic structure that underlies regularities  of the periodic table of elements. His atomic model had atoms built up of sucessive orbital shells of electrons. ]]> 2016-12-11 20:54:02 UTC https://padlet.com/491614/rwbraraohhg1/wish/143017358 491614 https://padlet.com/491614/rwbraraohhg1/wish/143017445 Using alpha particles discovered a neutral atomic particle with a mass close to a proton. then the neutron was discovered.]]> 2016-12-11 20:55:32 UTC https://padlet.com/491614/rwbraraohhg1/wish/143017445