THE HISTORY OF ATOMS by Mohamed Sardi https://padlet.com/mohamedsardi/fieznwmu4348prbk en-us 2023-02-08 11:26:04 UTC 2023-02-15 11:28:54 UTC hello@padlet.com https://padlet.net/icons/png/269b.png mohamedsardi https://padlet.com/mohamedsardi/fieznwmu4348prbk/wish/2474761595 DEMOCRITUS (440 BC)

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”. 




]]> 2023-02-09 09:59:24 UTC https://padlet.com/mohamedsardi/fieznwmu4348prbk/wish/2474761595 JOHN DALTON (1803) mohamedsardi https://padlet.com/mohamedsardi/fieznwmu4348prbk/wish/2481136542
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 08:44:27 UTC https://padlet.com/mohamedsardi/fieznwmu4348prbk/wish/2481136542 JJ THOMSON (1897) mohamedsardi https://padlet.com/mohamedsardi/fieznwmu4348prbk/wish/2481140029

He discovered negatively charged particles inside the atom (electrons). 


]]> 2023-02-14 08:48:05 UTC https://padlet.com/mohamedsardi/fieznwmu4348prbk/wish/2481140029 ERNEST RUTHERFORD (1909-1911) mohamedsardi https://padlet.com/mohamedsardi/fieznwmu4348prbk/wish/2481141953

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 08:49:59 UTC https://padlet.com/mohamedsardi/fieznwmu4348prbk/wish/2481141953 mohamedsardi https://padlet.com/mohamedsardi/fieznwmu4348prbk/wish/2481143534 NIELS BOHR (1913)

He improved on Rutherford's model. He proposed that electrons move around the nucleus in certain paths called energy levels. 


]]> 2023-02-14 08:51:41 UTC https://padlet.com/mohamedsardi/fieznwmu4348prbk/wish/2481143534 SCHRODINGER AND HEISENBERG (1926) mohamedsardi https://padlet.com/mohamedsardi/fieznwmu4348prbk/wish/2481168113

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


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