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460
Democritus
lived in the 460-457 BC
His philosophy was that everything was composed of atoms. There empty space between atom and there are different sizes and shapes of atoms. -
John Dalton
lived 1766-1844
The four main ideas of his theory;
1:All matter is made of atom.
2:Compound are formed by a combination of two or more
3:Atoms can be either created or destroyed
4:a chemical reaction is a rear reangement of atoms
In 1803 Dalton proposed his model named as "Daltons Law" -
Alchemists
Alchemists developed and contributed the tools and tech. for chemistry -
Joseph John Thomson
lived 1856-1940
He proposed his model in 1897
He used the Cathode Ray tube to make his discovery
The name of his model is "Plum Pudding"
His discovery was the electron -
Ernest Rutherford
He lives !871-1937
In 1911 he made his discovery
He was the student of J.J Thomson
His famous experiment was is the Gold foil
He discovered that atoms are made up of empty spaces
His model didnt explain the process of rediation of atoms -
Nieil Bohr
He lived 1885-1962
In 1927 he created his model
Thomson was his teacher
His model showed that the atoms are small, posittively charged nucleus surrounded electrons. also that electrons travel in separate orbits around the nucleus. -
James Chadwick
Chadwick lived 1891-1974
He made his discover in1932
He discovered Neutron
