History of Atoms by Sam Jorgensen https://padlet.com/jse606287/62713u76ajop356f srgshthbvvrdrsa en-us 2020-09-30 12:44:44 UTC 2025-10-21 18:40:14 UTC hello@padlet.com Theory jse606287 https://padlet.com/jse606287/62713u76ajop356f/wish/791020871 Democritus
500 BC

Theory: Everything is made of tiny particles called "Atomos", meaning indivisible.]]> 2020-09-30 12:47:34 UTC https://padlet.com/jse606287/62713u76ajop356f/wish/791020871 Billiard Ball Model jse606287 https://padlet.com/jse606287/62713u76ajop356f/wish/791099891 John Dalton
Early 1800s

Evidence: Air cannot be infinitely compressed

Conclusion: Air is made of tiny, uncompressable invisible spheres.]]> 2020-09-30 13:09:27 UTC https://padlet.com/jse606287/62713u76ajop356f/wish/791099891 Plum Pudding Model jse606287 https://padlet.com/jse606287/62713u76ajop356f/wish/791114499 J. J. Thompson
Late 1800s

Evidence: Negatively charged laser is repelled by matter

Conclusion: Atoms are a positive "dough" with negative particles stuck inside it]]> 2020-09-30 13:12:56 UTC https://padlet.com/jse606287/62713u76ajop356f/wish/791114499 Planetary Model jse606287 https://padlet.com/jse606287/62713u76ajop356f/wish/797590831 Neil's Bohr
1913

Evidence: According to the Nuclear Model, the electrons should crash into the nucleus.

Conclusion:  Electrons are confined to "Energy levels", and orbit the nucleus.]]> 2020-10-02 13:40:58 UTC https://padlet.com/jse606287/62713u76ajop356f/wish/797590831 Electron Cloud Model jse606287 https://padlet.com/jse606287/62713u76ajop356f/wish/797601154 Erwin Schrödinger
1927

Evidence: Electrons move so quickly that it's impossible to predict exactly where one is.

Conclusion: Atoms don't move in fixed orbits, and we can estimate aproximately where they'll be.]]> 2020-10-02 13:43:34 UTC https://padlet.com/jse606287/62713u76ajop356f/wish/797601154 Neutrons jse606287 https://padlet.com/jse606287/62713u76ajop356f/wish/797632374 James Chadwick
1932

Evidence: Atoms have more mass than is accounted for in the protons.

Conclusion: Neutrons exist in the nucleus and have no charge.]]> 2020-10-02 13:51:15 UTC https://padlet.com/jse606287/62713u76ajop356f/wish/797632374 Nuclear Model jse606287 https://padlet.com/jse606287/62713u76ajop356f/wish/797719471 Ernest Ruthorford
Early 1900s

Evidence: Beam usually goes through gold foil, but occasionally bounces back.

Conclusion: Atoms are a nucleus with electrons scattered around it.]]> 2020-10-02 14:12:41 UTC https://padlet.com/jse606287/62713u76ajop356f/wish/797719471