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500
Democritus
He was born in 460bc and died 370bc. Matter is made up of small particles which he called atoms. He used logical thinking. -
John Dalton
All matter is composed of tiny particles called atoms. He studied the evaporation of water into the air and was able to understand that the process increased gas pressure. -
JJ Thomson
Thomson identified the electron which carries a negative charge. They showed that different gases placed in the tubes gereated streams of particles and conducted current. -
Ernest Rutherford
Ernest hypothesized that an atom must be made up of mostly empty space, alpha particles to pass through foil. He used high-speed lightwieght atoms called alpha particles to bombard very thin pieces of gold foil. -
Albert Einstein
he discovered his special theory of relativity stemmed from an attempt to reconcile the law of mechanics with the laws of the electromagenetic field. Einstein always appeared to have clear view problems of physics and the determination to solve them. He had of his own and was able to visualize the main stages on the way to his goal. -
Neils Bohr
He described electrons as moving around the nucleus in fixed orbits that have a set amount of energy. His info about hature emissin of light by heated objects to update his model. -
James Chadwick
Finally solved the problem, he identified the third important subatomic particles, the neutron. He based on his work on earlier experiments by French physicists irene and frederic jolit