By: Leah Sylvester and Allison Kodroff

John Dalton

Born September 6, 1766, died July 27, 1844.

Born in Eaglesfield EnglandColorblind

Just like his older brother

Bio

Most of his life a teacher at a Quaker SchoolHe moved to another teaching job in

Manchester at the New College.Teaching math and philosophy

While there, he pursued his interest in meteorology

Found research on atmospheric pressure and he published it in his 1st book.

Early Life

Also researched color blindness.Since it affected both him and

his bother.Created a theory that color

blindness was genetic.His theory was proven true.

Contributions to the understanding of the re-green color blindness—Daltonism

B/c of his interest in atmospheric pressure this lead to a closer look at gases

Accomplishments

His theory: Matter can’t be divided into smaller and smaller pieces forever, eventually the smallest possible piece would be obtained.

This piece would be indivisible. He named the smallest piece of matter “atomos,” meaning “not to be cut.”

Atoms were hard particles made of the same material but different shapes and sizes. Atoms were infinite in number, always moving and capable of joining together.

Democritus

Used some of Democritus’ theory of matter.Borrowed the term “atom” to label the

particles.Created the 1st chart of atomic

weights.Published in his book where he expands

on the subject.A New System of Chemical Philosophy

introduced belief that atoms of differ elements could be distinguished based on their atomic weight

Atomic Theory

Law of Multiple Proportions (sometimes called Dalton's Law): If two elements form more than one compound between them, the ratios of the masses of the 2nd element combined with the mass of the 1st element will be ratios of small whole numbers.

Atomic Theory

Elements are made of extremely small particles called atoms.

Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties.

Five Main Points of Dalton's Atomic Theory

Atoms cannot be subdivided, created, or destroyed.

Atoms of different elements combine in simple whole-number ratios to form chemical compounds.

In chemical reactions, atoms are combined, separated, or rearranged.

Five Main Points of

Dalton's Atomic Theory

Dalton’s atomic theory was not all correct…Dalton thought atoms were indivisible atoms

are divisibleAtoms of a given element have identical

properties atoms of the same element have slightly different masses

A chemical reaction to rearrange atoms atoms can only be destroyed by chemical reactions

Atomic Theory

http://www.iun.edu/~cpanhd/C101webnotes/composition/dalton.html

Chemistry Matter and Changehttp://www.biography.com/people/john-dalton-

9265201

sources