My fancy padlet by Russell Johnson https://padlet.com/johnruss3728/lhtwgnv2o1b1nqp1 en-us 2022-11-07 19:04:09 UTC 2025-11-17 22:19:48 UTC hello@padlet.com 440 B.C Democritus johnruss3728 https://padlet.com/johnruss3728/lhtwgnv2o1b1nqp1/wish/2373706605 1. Atoms are small hard particles
2. Uncut able
3. Atoms constantly move.

]]> 2022-11-07 19:13:26 UTC https://padlet.com/johnruss3728/lhtwgnv2o1b1nqp1/wish/2373706605 1803 John Dalton johnruss3728 https://padlet.com/johnruss3728/lhtwgnv2o1b1nqp1/wish/2373709383 1. All substances are made of atoms
2. Atoms of different elements are different 
3. He conducted experiments in combining elements
]]> 2022-11-07 19:15:13 UTC https://padlet.com/johnruss3728/lhtwgnv2o1b1nqp1/wish/2373709383 1897 Thomson johnruss3728 https://padlet.com/johnruss3728/lhtwgnv2o1b1nqp1/wish/2373719623 1. “Plum” pudding or chocolate chip model
2. Small negatively (-) charges particles in the atom
3. Thomson's experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons.
]]> 2022-11-07 19:21:32 UTC https://padlet.com/johnruss3728/lhtwgnv2o1b1nqp1/wish/2373719623 1911 Rutherford johnruss3728 https://padlet.com/johnruss3728/lhtwgnv2o1b1nqp1/wish/2373722956 1. Most of the atom’s mass is in the nucleus
2. Small dense positively charged nucleus
3. Atoms contain mostly empty space
4. Electrons move in the empty space of the atoms
]]> 2022-11-07 19:23:45 UTC https://padlet.com/johnruss3728/lhtwgnv2o1b1nqp1/wish/2373722956 1913 Bohr johnruss3728 https://padlet.com/johnruss3728/lhtwgnv2o1b1nqp1/wish/2373726918 1. Bohr proposed a theory for the hydrogen atom, based on quantum theory that some physical quantities only take discrete values.
2. Electrons travel in definite paths
3. Electrons ‘jump’ between levels from path to path
]]> 2022-11-07 19:26:24 UTC https://padlet.com/johnruss3728/lhtwgnv2o1b1nqp1/wish/2373726918 20th century Schrodinger and Heisenberg johnruss3728 https://padlet.com/johnruss3728/lhtwgnv2o1b1nqp1/wish/2373732200 1. Electron paths cannot be predicted
2. Electrons are found in electron clouds.
3. They mathematically determined regions in which electrons would be most likely found.
]]> 2022-11-07 19:29:49 UTC https://padlet.com/johnruss3728/lhtwgnv2o1b1nqp1/wish/2373732200