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Democritus (400 B.C.)
Democritus claimed that everything is made up of atoms. He said that "these atoms change physically, but not geometrically, indivisible."
He thought that the atom looked likenan inert solid that mechanically interacts with other atoms. He called the atom the "Democritean Atom." -
Dalton
Dalton wanted to have both the exitence of both molecules and atoms.
He created "Dalton's Atomic Theroy" which consisted of the conservation of mass, law of definite proportions, law of multiple proportions, Einstein's theory of relativity, & the number of atoms in the universe. -
Thomson
Thomson tested Rutherford's "Gold Foil Experiment" and discovered that the mass of atom is spread throughout the entire atom.
He soon developed the "Planetary Model" which put out all the protons in the nucleus and the electrons orbiting around the nucleus. -
Rutherford
Rutherford and his co-workers discovered that an atom has a nucleus. Most atoms have empty space with the nucleus in the middle. Sometimes, the olpha particles will bounce off the nucleus and go off course.
Rutherford and his co-workers called the atom the "Plum-Pudding Atom." They thought that it looked like a blueberrry muffin with blueberries stuck inside the dough.
