Atomic Model Timeline by James Clarke https://padlet.com/s9104160/vigxt27ibwar32sq en-us 2021-08-24 19:45:32 UTC 2021-08-26 19:55:34 UTC hello@padlet.com Democritus (460 B.C - 370 B.C) s9104160 https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1694324535 Democritus was a Greek philosopher and believed the world was made of empty space and tiny bits of "stuff". He called them atoms, the Greek word for atomos meaning cannot be divided.

 - 370 B.C)
]]> 2021-08-24 19:50:42 UTC https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1694324535 John Dalton (1808) s9104160 https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696143399 John Dalton was an English Chemist and schoolteacher. He thought that atoms made up matter and could not be seen with the naked eye. Also, he thought that each element was made of only 1 atom.]]> 2021-08-25 14:29:30 UTC https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696143399 J.J. Thomson (1897) s9104160 https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696153331 J.J. Thomson was an English Chemist that discovered the presence of negatively charges particles in atoms called electrons. He proved this by using a Cathode ray tube and created an atomic model known as the "plum pudding" model.]]> 2021-08-25 14:33:44 UTC https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696153331 Ernest Rutherford (1909) s9104160 https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696694765 Rutherford discovered that each atom had a center, called the nucleus, that was positively charged. He found that the electrons were in mostly empty space and were orbiting the nucleus.]]> 2021-08-25 19:15:39 UTC https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696694765 Niels Bohr (1919) s9104160 https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696698828 Bohr thought that the electrons moved in a circular path around the nucleus at different energy levels. This would go on to help scientist predict chemical properties of elements.]]> 2021-08-25 19:18:38 UTC https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696698828 James Chadwick (1932) s9104160 https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696702516 Chadwick was a student of Rutherford's and continued to study atoms. He found that the nucleus had uncharged particles inside, and called these neutrons.]]> 2021-08-25 19:21:07 UTC https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696702516 Dmitri Mendeleev (1869) s9104160 https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696711237 Dmitri Mendeleev was a Russian Chemist and created the framework for the modern periodic table. He fit the atoms in to groups and put them in order based on their atomic weight.]]> 2021-08-25 19:26:38 UTC https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696711237 Pierre and Marie Curie (1898) s9104160 https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696721281 These 2 French Physicist found 2 very radioactive elements, polonium and radium. Marie created the term "radioactivity" for the release of spontaneous ionizing rays. ]]> 2021-08-25 19:33:35 UTC https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696721281 Robert Millikan (1910) s9104160 https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696733316 In Millikan's experiment with drops of oil he found that electrons have a fundamental electric charge. This means that each electron has a charge that is a multiple of a single number.]]> 2021-08-25 19:42:15 UTC https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1696733316 Plum Pudding model (1904) s9104160 https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1698271157 Created by J.J. Thomson after the discovery of the electron, which had the electrons in a positively charged fluid. ]]> 2021-08-26 11:21:54 UTC https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1698271157 Billiard Ball Model (1808) s9104160 https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1698274673 John Dalton created the Billiard Ball model in 1808. He thought they were small, hard, and hollow spheres.]]> 2021-08-26 11:26:07 UTC https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1698274673 Solar System Model (1919) s9104160 https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1698277857 Created by Niels Bohr, the atom was believed to be like a solar system. The electrons would orbit around the nucleus.]]> 2021-08-26 11:29:41 UTC https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1698277857 Electron Cloud Model (Current) s9104160 https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1699181879 The current atomic model is the electron cloud model. It has the nucleus in the center made of protons in neutrons. Sine the electrons move so fast, there is a cloud where they are located.]]> 2021-08-26 19:52:08 UTC https://padlet.com/s9104160/vigxt27ibwar32sq/wish/1699181879