THE HISTORY OF THE ATOM by Aroa Juaristi Seijas https://padlet.com/aroajuaristi/r98clyx1zvkobdgv Everything is made of atom. en-us 2023-02-14 11:09:05 UTC 2025-12-05 12:42:20 UTC hello@padlet.com https://padlet.net/icons/png/1f9ea.png DEMOCRITUS (440 BC) aroajuaristi https://padlet.com/aroajuaristi/r98clyx1zvkobdgv/wish/2481589776

He proposed that matter could not be divided into smaller pieces forever. He said that matter was made of small, hard particles that he called “atoms”. 


]]> 2023-02-14 11:17:51 UTC https://padlet.com/aroajuaristi/r98clyx1zvkobdgv/wish/2481589776 JOHN DALTON (1803) aroajuaristi https://padlet.com/aroajuaristi/r98clyx1zvkobdgv/wish/2481593205

He created the very first atomic theory. 
All substances are made of atoms. Atoms are small particles that cannot be created, divided, or destroyed. Atoms are invisible.
Atoms join together to make new substances (molecules).


]]> 2023-02-14 11:19:04 UTC https://padlet.com/aroajuaristi/r98clyx1zvkobdgv/wish/2481593205 JJ THOMSON (1897) aroajuaristi https://padlet.com/aroajuaristi/r98clyx1zvkobdgv/wish/2481596385 He discovered negatively charged particles inside the atom (electrons). 


]]> 2023-02-14 11:20:05 UTC https://padlet.com/aroajuaristi/r98clyx1zvkobdgv/wish/2481596385 ERNEST RUTHERFORD (1909-1911) aroajuaristi https://padlet.com/aroajuaristi/r98clyx1zvkobdgv/wish/2481606141

He proposed that in the center of the atom is positively charged part called the nucleus. He discovered the protons and nucleus. 


]]> 2023-02-14 11:23:48 UTC https://padlet.com/aroajuaristi/r98clyx1zvkobdgv/wish/2481606141 NIELS BOHR (1913) aroajuaristi https://padlet.com/aroajuaristi/r98clyx1zvkobdgv/wish/2481608397 He improved on Rutherford's model. He proposed that electrons move around the nucleus in certain paths called energy levels. 


]]> 2023-02-14 11:24:33 UTC https://padlet.com/aroajuaristi/r98clyx1zvkobdgv/wish/2481608397 SCHRODINGER AND HEISENBERG (1926) aroajuaristi https://padlet.com/aroajuaristi/r98clyx1zvkobdgv/wish/2481611880

He proposed that electrons do not travel in definite paths around the nucleus.


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