Atomic Timeline by ANH T. NGU https://padlet.com/an238437/x9asz3ddl2hkec6g en-us 2020-09-29 19:19:22 UTC 2020-09-30 19:46:03 UTC hello@padlet.com https://padlet.net/icons/png/1f9ea.png Democritus | 400 BCE an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789402263 ♡ Introduced the idea that atoms are the basic building blocks of mater. 
♡ Believed that atoms are tiny, uncuttable, solid particles that are surrounded by empty space and constantly moving at random. 
]]> 2020-09-29 19:26:16 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789402263 J.J Thomson | 1897 an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789419480 ♡ Discovered he electron by experimenting with a Crookes, or cathode ray, tube.
♡ Also found the first evidence that stable elements can exist as isotopes.
♡Invented the mass spectometer.]]> 2020-09-29 19:31:31 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789419480 Niels Bohr | 1913 an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789431353 ♡ Proposed a model of the atom in which the electron was able to occupy only certain orbits around the nucleus. 
♡ This model was he first to use quantum theory.]]> 2020-09-29 19:35:12 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789431353 Ernest Rutherford | 1911 an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789433711 ♡ Discovered the nucleus of the atom
♡ The experiment showed the existence of a nuclear atom - a small, positively-charged nucleus surrounded by empty space and then a layer of electrons to form the outside of the atom.]]> 2020-09-29 19:35:57 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789433711 John Dalton | 1803 an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789458530 ♡ First introduced the atomic theory.
♡ Developed methods to calculate atomic weights and structures and formulated the law of partial pressures.

]]> 2020-09-29 19:44:09 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789458530 Marie & Pierre Curie | 1898 an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789460115 ♡ Discovered the existence of the elements radium and polonium in their research of pitchblende.
♡ In 1902, they successfully isolate radioactive radium salts from the mineral pitchblende]]> 2020-09-29 19:44:40 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789460115 Robert Millikan | 1910 an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789551153 ♡ Discovered the elementary charge of an electron using the oil-drop experiment.

]]> 2020-09-29 20:17:09 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789551153 Albert Einstein | 1905 an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789587491 ♡ Mathematically proved the existence of atoms, and thus helped revolutionize all the sciences through the use of statistics and probability.]]> 2020-09-29 20:31:24 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789587491 James Chadwick | 1932 an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789589513 ♡ Made a fundamental discovery in the domain of nuclear science: he proved the existence of neutrons – elementary particles devoid of any electrical charge.]]> 2020-09-29 20:32:16 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/789589513 Michael Faraday | 1831 an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/792747634 ♡ Discovered electromagnetic induction
♡ Repeated Oersted's experiment placing a small magnet around a current-carrying wire and verified that the force exerted by the current on the magnet was circular.]]> 2020-09-30 19:20:43 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/792747634 Max Planck | 1900 an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/792758486 ♡ Discovered the quantum of action, now knwn as Planck's constant. ]]> 2020-09-30 19:24:11 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/792758486 Antoine Lavoisier | 1772-1794 an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/792762279 ♡ Determined that oxygen was a key substance in combustion, and he gave the element its name. 
♡ Has been called the "father of modern chemistry"]]> 2020-09-30 19:25:26 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/792762279 Joseph Louis Proust | 1794 an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/792786976 ♡ First published his Law of Definite Proportions (or Law of Constant Composition) .
♡ Regardless of how the compound was created.]]> 2020-09-30 19:33:14 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/792786976 Henri Becquerel | 1896 an238437 https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/792802856 ♡ Discovered radioactivity in uranium.
♡ Made scientists radically change their ideas about atomic structure. Radioactivity demonstrated that the atom was neither indivisible nor immutable.]]> 2020-09-30 19:38:21 UTC https://padlet.com/an238437/x9asz3ddl2hkec6g/wish/792802856