1803, Dalton's Atomic Theory

Photo Credit: johndalton.org

Year: 1803
Chemist: John Dalton
Contribution: John Dalton's Atomic Theory

Around the year 1803, the English chemist John Dalton proposed his atomic theory to the Royal Institution. He projected a few standard ideas, for example:

• all matter is made of atoms
• atoms are indestructible, but neither can they be made
• an element's atoms are identical
• an element's atomic structure is unique—different elements have different compositions
• rearranging atoms causes chemical reactions
• compounds are formed by the atoms of the elements within

To his way of thinking atoms were solid spheres, and based his thoughts on the massing of elements. Dalton unfortunately had a few flaws in the entirety of his theory, but his explanation provoked advancement in investigation.


Information Credits: Royal Society of Chemistry, Atomic Structure Timeline