John Dalton

“ We might as well attempt to introduce a new planet into the solar system, or to annihilate one already in existence, as to create or destroy a particle of hydrogen.”

Time Period: 1768 - 1828

Background: John Dalton, British chemist and physics, is responsible for developing the atomic theory of matter and is there credited as one of the fathers of modern physical science. A teacher of natural philosophy and mathematics, he taught at New College in Manchester. From then until his death, he was president of the Philosophical Society.

Belief: Dalton believed in three main ideas which eventually made up his atomic theory - 1. elements cannot be broken down into simpler substances 2. conservation of mass 3. law of constant composition or definite proportions. He combined these theories into one, and created Dalton's Atomic Theory. It stated that all elements are composed of atoms, that all atoms of the same element are identical with the same mass, that atoms of one kind of element differ in those of another, that they are indestructible and retain their identity in chemical reactions, and that compounds are formed by joining atoms in specific whole number ratios.

Contribution: Dalton's contribution not only gave science the first Atomic Theory based on experimental evidence, it also triggered an explosive investigation on matter which still follows into today.