-
460
Democritus' Theory. (my topic)
Democritus found that atoms were the simplest form of matter and could not be broken down, split, destroyed, or changed in any way.
Democritus said, "by convention bitter, by convention sweet, but in reality atoms and void", when referring to his discovery of atoms. -
Dalton's Theory
-All matter is formed of atoms
-atoms are indivisible
-atoms of the same element are of the same mass
-atoms that make compounds are of set proportions
-chemical changes reorganize the atoms -
Thomson's Theory
Thomson had discovered that atoms are composite objects, made of pieces with positive and negative charge, and that the negatively charged electrons within the atom were very small compared to the entire atom. He therefore proposed that atoms have structure similar to a plum pudding, with tiny, negatively charged electrons embedded in a positively charged substrate. This was later shown to be incorrect. -
Ernest Rutherford's Theory
He founded the nucleus was the center of the atoms charge and held all of it's mass. He also disproved the plum pudding model. -
Bohr's Theory
He said the atom is a small positiviely charged nucleus surrounded by electrons held in an orbit. -
Quantum-Mechanical Theory
a fundamental branch of physics concerned with processes involving, for example, atoms and photons.
