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Period: 350 to 470
Atomic History Timeline
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400
Democritus
A greek philosepher who theorized everything was made up of small little particles. -
John Dalton
Credited for making atomic theory. Each chemical element is composed of extremely small particles that are indivisible and cannot be seen by the naked eye, called atoms. Atoms can neither be created nor destroyed. -
Period: to
Dalton
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Period: to
Thomson
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Period: to
Rutherford
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J.J Thomson
Discovered the Electron in a series of tests to discover the nature of electric discharge. -
Period: to
Curie
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Madam Curie
Madam Curie got her first Noble Prize in 1903 in physics, shared with Pierre Curie (her husband) and Henri Becquerel for the discovery of the phenomenon of radioactivity -
Period: to
Bohr
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Ernest Rutherford
His model described the atom as a tiny, dense, positively charged core called a nucleus, in which nearly all the mass is concentrated, around which the light, negative constituents, called electrons circulate at some distance, much like planets revolving around the Sun -
Niels Bohr
The Bohr Model has an atom consisting of a small, positively-charged nucleus orbited by negatively-charged electrons. Niels Bohr proposed the Bohr Model of the Atom in 1915. Because the Bohr Model is a modification of the earlier Rutherford Model -
Period: to
Schrodinger
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Erwin Schrödinger
He took the Bohr atom model one step further. Schrödinger used mathematical equations to describe the likelihood of finding an electron in a certain position. This atomic model is known as the quantum mechanical model of the atom. Unlike the Bohr model, the quantum mechanical model does not define the exact path of an electron, but rather, predicts the odds of the location of the electron. This model can be portrayed as a nucleus surrounded by an electron cloud.
