THE HISTORY OF THE ATOM by Sara Essayad https://padlet.com/saraessayad/6tt0ibm2vw09f7c3 Everything is made of atoms en-us 2023-02-14 11:09:51 UTC 2023-02-15 09:19:40 UTC hello@padlet.com https://padlet.net/icons/png/1f52e.png DEMOCRITUS (440 BC) saraessayad https://padlet.com/saraessayad/6tt0ibm2vw09f7c3/wish/2481594928

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 11:19:36 UTC https://padlet.com/saraessayad/6tt0ibm2vw09f7c3/wish/2481594928 JOHN DALTON (1803) saraessayad https://padlet.com/saraessayad/6tt0ibm2vw09f7c3/wish/2481615586

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 11:26:33 UTC https://padlet.com/saraessayad/6tt0ibm2vw09f7c3/wish/2481615586 JJ THOMSON (1897) saraessayad https://padlet.com/saraessayad/6tt0ibm2vw09f7c3/wish/2481621179

 

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





]]> 2023-02-14 11:28:16 UTC https://padlet.com/saraessayad/6tt0ibm2vw09f7c3/wish/2481621179 ERNEST RUTHERFORD (1909-1911) saraessayad https://padlet.com/saraessayad/6tt0ibm2vw09f7c3/wish/2483191503 1911)He proposed that in the center of the atom is positively charged part called the nucleus. He discovered the protons and nucleus. ]]> 2023-02-15 09:12:42 UTC https://padlet.com/saraessayad/6tt0ibm2vw09f7c3/wish/2483191503 NIELS BOHR (1913) saraessayad https://padlet.com/saraessayad/6tt0ibm2vw09f7c3/wish/2483192720

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


]]> 2023-02-15 09:13:50 UTC https://padlet.com/saraessayad/6tt0ibm2vw09f7c3/wish/2483192720 SCHRODINGER AND HEISENBERG (1926) saraessayad https://padlet.com/saraessayad/6tt0ibm2vw09f7c3/wish/2483194520

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


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