Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Unit 7: Periodic Table Chapters 6 & 7 Chemistry 1K Cypress Creek High School Part 1: History of the Periodic Table Johann Wolfgang Döbereiner German chemist 1780-1849 Noticed that there was a pattern in the atomic masses and atomic numbers of certain elements These sets of patterns became known as “Döbereiner's triads” Johann Wolfgang Döbereiner John Newlands English chemist 1837-1898 In 1865, proposed the Law of Octaves whereby every eighth element has similar properties. John Newlands Dmitri Mendeleev Russian chemist 1834-1907 Arranged periodic table by increasing atomic mass Aligned properties in vertical columns Some elements fell into the wrong column lik Te & I ; Co & Ni Dmitri Mendeleev Henry Moseley English physicist 1887-1915 Rearranged the modern table by atomic number Used X-ray spectrometer to find the atomic numbers Henry Moseley