Science Time Line by Elizabeth Keaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk Elizabeth Keaton en-us 2018-09-21 13:52:57 UTC 2018-09-21 18:41:42 UTC hello@padlet.com Democritus 430 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284376414 Proposed the first idea of objects being made up of tiny invisible particles called atomos or atoms.]]> 2018-09-21 13:56:04 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284376414 John Dalton 1811 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284377753 Law of multiple proportions, statement that when two elements combine with each other to form more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.
Proposed first atomic theory
1 all matter is made up of atoms
2 atoms of same elements are the same
3 atoms of different elements are different
4 atoms combine in whole number ratios to make compounds

]]> 2018-09-21 13:58:07 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284377753 JJ Thomson 1897 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284518485 Used cathode rays to discover the electron measured the bending of the rays to determine the charge to mass ratio of the electron
Modified cathode ray tubes were used to discover the positively charged proton]]> 2018-09-21 18:31:29 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284518485 Ernest Rutherford 1911 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284518723 Studied substances like alpha particles
Conducted gold foil experiments: He bombarded goil foils with alpha particles. Most particles passed through the foils, but some were deflected. He concluded that the atoms is mostly empty space, with a very small positive nucleus core
Nuclear Model]]> 2018-09-21 18:32:02 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284518723 Niel Bohr 1913 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284518956 Improved upon the atomic model by trying to answer the question: Why aren’t electron pulled into the nucleus?
Electrons travel in definite energy levels without radiating energy
Electrons in each orbit have a certain amount of energy
Electrons increase as distance from the nucleus increases
Electrons lose energy by dropping energy levels

]]> 2018-09-21 18:32:34 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284518956 Erwin Schrodinger 1926 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284519164 Schrodinger’s wave equation 
Treat the electron like a wave
Developed an equation used to determine the probability of finding the electron in any given place around the nucleus 
Solutions to the equation are quantum numbers
Quantum Model]]> 2018-09-21 18:33:00 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284519164 James Chadwick 1932 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284519371 Discovered the neutron]]> 2018-09-21 18:33:28 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284519371 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284520158   ]]> 2018-09-21 18:35:14 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284520158 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284521201 2018-09-21 18:37:42 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284521201 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284521464 2018-09-21 18:38:18 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284521464 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284521737 2018-09-21 18:38:56 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284521737 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284521869 2018-09-21 18:39:15 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284521869 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284522186 2018-09-21 18:39:56 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284522186 elizabethkeaton https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284522417 2018-09-21 18:40:23 UTC https://padlet.com/elizabethkeaton/bpc2bk86d9fk/wish/284522417