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Dalton's Model of the Atom / J.J. Thomson / Millikan's Oil Drop Experiment / Rutherford / Niels Bohr / DeBroglie / Heisenberg / Planck / Schrödinger / Chadwick

Before we can discuss Dalton's Model of the atom, I must first mention the Law of Multiple Proportions. Simply put, when elements combine to form compounds they do so in whole number ratios.

Carbon and Oxygen can form either CO ( a 1:1 ratio) or CO₂ (a 1:2 ratio). It also states that if the mass of the first element is constant the second elements masses would be in a whole number ratio.

1.00g of Carbon will have combined with 1.33g in CO

1.00g of Carbon will have combined with 2.66g in CO₂

The mass are in a 1:2 ratio

Simply put if combinations are in whole number ratios, there must be a one. This one being an atom. Here are Dalton's assumptions.

All matter is composed of atoms
Atoms cannot be made or destroyed
All atoms of the same element are identical
Different elements have different types of atoms
Chemical reactions occur when atoms are rearranged
Compounds are formed from atoms of the constituent elements.

Dalton's Model of the Atom / J.J. Thomson / Millikan's Oil Drop Experiment / Rutherford / Niels Bohr / DeBroglie / Heisenberg / Planck / Schrödinger / Chadwick

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