history of atomic therory

democritus

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Democritus was an Ancient Greek philosopher born in Abdera first person to think that everything is made of smaller things nown as atoms

john dalton

Sep 6, 1766

developed the modernt type of modern atomic theroy

ernest ruthford

Aug 30, 1871

he discoverd the nucleus in an atom

niels bohr

Oct 7, 1885

discoverd the struture of an atom

james chadwick

Oct 20, 1891

discoverd the nutron in the nuclious

j.j thomson

Feb 6, 1897

showed that cathode rays were composed of a previously unknown negatively charged particle