Jhon Dalton

Only available on StudyMode
  • Download(s) : 161
  • Published : September 11, 2012
Open Document
Text Preview
John Dalton was a born September 6, 1766 in Eagelsfield, Cumbria in England, but spent most of his life in Manchester. He was a British Chemist and physicist. He  was the son of Weaver and he received his early education from his father. At the age of 12 Dalton began teaching at Quacker School in his native town. In 1781 he moved  to Kendal, where he conducted a school with his cousin and his elder brother. He then went to Manchester in 1793 and spent the rest of his life in Manchester as a teacher, first at New College, and later as a private tutor. Dalton suffered a minor stroke in 1837, and a second one in 1838 left him with a speech impediment, though he remained able to do experiments. In May 1844 he had yet another stroke; on 26 July he recorded with trembling hand his last meteorological observation. On 27 July, in Manchester, Dalton fell from his bed and was found lifeless by his attendant. Approximately 40,000 people filed by his coffin as it was laid in state in the Manchester Town Hall. He was buried in Manchester in Ardwick cemetery. The cemetery is now a playing field, but pictures of the original grave are in published materials. Dalton was a life long bachelor.

Daltons First Major Step to the Atomic Theory

Daltons fascination with science included a intense interest in meteorology. Starting in 1793 John kept careful daily weather records for 46 years. The meteorology study  here led Dalton to a interest in the gases of the air and their ultimate components. This interest of gases led to Daltons discovery of the Atomic Theory

Dalton's Discovery

John Dalton was a humble man with several apparent handicaps: he was poor, he was not articulate, he was not a skilled experimentalist, and he was color blind. These  disadvantages are a terrible problem for a chemist, but in spite of these Dalton made his most important contribution to science called the atomic theory. Dalton was the first to prepare a table of relative atomic weights. He only listed 6 elements but he assigned an Atomic Weight of 1.0 to Hydrogen and then proposed weights for Oxygen, Nitrogen, Carbon, Sulfur, and Phosphorus. He further postulated that chemical combination takes place between particles of different weights, which differs from the explanations provided by the Ancient Greeks that matter is composed of atoms of differing weights and combine in simple ratio’s by weight. This theory which Dalton first advanced in 1803, is the cornerstone of modern physical science. Dalton's atomic theory rests on the following postulates:  1.All matter consists of tiny particles 

2.Atoms are indestructible and unchangeable 
3.Elements are characterized by the mass of there atoms 
4.When Elements react, their atoms combine in simple, whole-number ratios

Partial pressures

He discovered the law of partial pressures. Dalton's law states that pressure of nonreactive gaseous mixture is equal to a sum of pressures of each separate element of the mixture having the same volume as the mixture. Another Dalton's discovery, which he made in 1804, was showing that if two elements have more than one combination, then weight amounts of one of them belonging to the unchanging amount of the second one are staying in relations of small integers (the law of stoichiometry). For example, for chlorine oxides (Cl2O, Cl2O6, Cl2O7) masses of oxygen belonging to chlorine unit are staying in proportions 1:6:7. 

John Dalton
1766 – 1844

British chemist and physicist who developed the atomic theory of matter and hence is known as one of the fathers of modern physical science.

Early Life

John Dalton was born September 6, 1766 at Eaglesfield, near Cockermouth in the Lake District of Cumberland, Great Britian.1, 5 His father, Joseph Dalton, was a weaver in poor circumstances, who, with his wife (Deborah Greenup), belonged to the Society of Friends; they had three children; Jonathan, John and Mary.7

John received his early education from his father and...
tracking img