John Dalton: He Got the Ball Rolling

JOHN DALTON

John Dalton was born in Eaglesfield, Cumberland, England on September 6, 1766. He was a famous chemist, meteorologist and physicist. Dalton is best known for his pioneering work in the development of modern atomic theory, and his research into colour blindness (sometimes referred to as Daltonism, in his honor). John Dalton was one of the first scientists to decide that all matter is made up of small particles, or atoms. Around 1790, Dalton seems to have considered taking up law or medicine, but his projects were not met with encouragement from his relatives — Dissenters were barred from attending or teaching at English universities — and he remained at Kendal until, in the spring of 1793, he moved to Manchester. Also, Dalton was an appointed teacher of mathematics and natural philosophy at the "New College" in Manchester, a Dissenting academy until 1800, and published a book entitled "Elements of English Grammar" in 1801.

      In 1800, Dalton became a secretary of the Manchester Literary and Philosophical Society, and in the following year he orally presented an important series of papers, entitled "Experimental Essays" on the constitution of mixed gases; on the pressure of steam and other vapours at different temperatures, both in a vacuum and in air; on evaporation; and on the thermal expansion of gases. These four essays were published in the Memoirs of the Lit & Phil in 1802. Dalton proceeded to print his first published table of relative atomic weights. Six elements appear in this table, namely hydrogen, oxygen, nitrogen, carbon, sulfur, and phosphorus, with the atom of hydrogen conventionally assumed to weigh 1. Dalton provided no indication in this first paper how he had arrived at these numbers. However, in his laboratory notebook under the date 6 September 1803[4] there appears a list in which he sets out the relative weights of the atoms of a number of elements, derived from analysis of water, ammonia, carbon dioxide, etc. by chemists of the time. He died on July 27, 1844 due to a stroke.

Billiard Ball Model

There were FIVE Main Points on Dalton's Atomic Theory:

• Chemical elements are made of atoms
• The atoms of an element are identical in their masses
• Atoms of different elements have different masses
• Atoms only combine in small, whole, number ratios
• Atoms can neither be created nor destroyed

** The balls in the figure were used by Dalton in his experiments.

Events during Dalton's time (1766-1844)

• American Revolutionary War
• Decleration of Independence in the United States of America
• First European establishment in Australia at Sydney
• George Washington is elected as president
• French Revloution
• Bifocals were invented by Benjamin Franklin
• Antoine Lavoisier discovers the law of conservation of mass, the basis of chemistry, and begins modern chemistry

Group 4

Dimalanta

Conanan

Lising

Montalbo