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Dalton's theory
In 1803 He proposed these ideas. (1) Elements consist of indivisible small particles (atoms). (2) All atoms of the same element are identical; different elements have different types of atom. (3) Atoms can neither be created nor destroyed. -
Thomsons theory
On April 30, 1897, British physicist J.J. Thomson announced his discovery that atoms were made up of smaller components. Thomson's experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons. Thomson proposed the plum pudding model of the atom, which had negatively-charged electrons embedded within a positively-charged "soup." -
Rutherfords theory
in may of 1911 Rutherford stated , The positively charged particles and most of the mass of an atom was concentrated in an extremely small volume. He called this region of the atom as a nucleus. Rutherford model proposed that the negatively charged electrons surround the nucleus of an atom. -
Bohr Theory
In 1913, Niels Bohr proposed a theory for the hydrogen atom, based on quantum theory that some physical quantities only take discrete values.In 1913, Niels Bohr proposed a theory for the hydrogen atom, based on quantum theory that some physical quantities only take discrete values.
