THE HISTORY OF THE ATOM by Badr Eddine Sadik https://padlet.com/badrsadik1/rb215dqt7d8hlt5y Everything is made of ATOMS. Thet are eally small particles. en-us 2023-02-14 09:27:06 UTC 2026-02-10 04:37:08 UTC hello@padlet.com https://padlet.net/icons/png/269b.png DEMOCRITUS (440 BC) badrsadik1 https://padlet.com/badrsadik1/rb215dqt7d8hlt5y/wish/2481308843

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 09:29:51 UTC https://padlet.com/badrsadik1/rb215dqt7d8hlt5y/wish/2481308843 JOHN DALTON (1803) badrsadik1 https://padlet.com/badrsadik1/rb215dqt7d8hlt5y/wish/2481311892

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 09:30:39 UTC https://padlet.com/badrsadik1/rb215dqt7d8hlt5y/wish/2481311892 JJ THOMSON (1897) badrsadik1 https://padlet.com/badrsadik1/rb215dqt7d8hlt5y/wish/2481320391 He discovered negatively charged particles inside the atom (electrons). 


]]> 2023-02-14 09:32:54 UTC https://padlet.com/badrsadik1/rb215dqt7d8hlt5y/wish/2481320391 ERNEST RUTHERFORD (1909-1911) badrsadik1 https://padlet.com/badrsadik1/rb215dqt7d8hlt5y/wish/2481343166 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 09:38:47 UTC https://padlet.com/badrsadik1/rb215dqt7d8hlt5y/wish/2481343166 NIELS BOHR (1913) badrsadik1 https://padlet.com/badrsadik1/rb215dqt7d8hlt5y/wish/2481348359 He improved on Rutherford's model. He proposed that electrons move around the nucleus in certain paths called energy levels. 


]]> 2023-02-14 09:40:10 UTC https://padlet.com/badrsadik1/rb215dqt7d8hlt5y/wish/2481348359 SCHRODINGER AND HEISENBERG (1926) badrsadik1 https://padlet.com/badrsadik1/rb215dqt7d8hlt5y/wish/2481352724 He proposed that electrons do not travel in definite paths around the nucleus.


]]> 2023-02-14 09:41:20 UTC https://padlet.com/badrsadik1/rb215dqt7d8hlt5y/wish/2481352724