John+Dalton+Hall

=__ John Dalton(1766-1844) __ = =[] John Dalton (September 6, 1766 – July 27, 1844) was an English chemist and physicist. Dalton is best known for his work on atomic theory and research into color blindness. His work was done around the time of 1805 and beyond. It was mostly done at Manchester college, along with summer visits in Cumbria. = **__Work on Meteorology__** Influenced by a friend of his family, an amateur weather observer, Dalton became deeply interested in meteorology. In 1787 he began a daily journal of weather observations that he painstakingly maintained for over 40 years. In 1793 he published a definitive work called //Meteorological Observations and Essays//. In 1793, Dalton became a teacher of mathematics and natural philosophy at Manchester Academy. __**Work on Color Blindness**__ In 1794, Dalton was elected a member of the Manchester Literary and Philosophical Society. A few weeks after his election he communicated his first paper on //Extraordinary Facts Relating to the Vision of Colours//, in which he postulated that shortage in color perception was caused by discoloration of the liquid medium of the eyeball. What makes this paper so remarkable is that a shortage of color perception -- "color blindness" -- had not even been formally described or even officially noticed by the scientific community until Dalton wrote about his own visual problem. Although Dalton's theory lost credence in his own lifetime, the thorough, methodical nature of his research was so broadly recognized that "Daltonism" is still a common term for color blindness **__Work on Gases__** Dalton became a secretary of the Manchester Literary and Philosophical Society in 1800. In 1801 he presented a series of papers entitled //Experimental Essays// on the constitution of mixed gases; on the pressure of steam and other vapors at different temperatures, both in a vacuum and in air; on evaporation; and on the thermal expansion of gases. In these essays he concluded, among other things, that the variation of vapor pressure for all liquids is equivalent, for the same variation of temperature, reckoning from vapor of any given pressure**.**

__ Five main points of Dalton's Atomic Theory __ 1.)Elements are made of tiny particles called atoms 2.) All atoms of a given element are identical 3.)The atoms of a given element are different from those of any other element: the atoms of different elements can be distinguished from one another by their respective relative atomic weights. 4.)Atoms of one element can combine with atoms of other elements to form chemical compounds: a given compound always has the same relative numbers of types of atoms 5.)Atoms cannot be created, divided into smaller particles, nor destroyed in the chemical process; a chemical reaction    simply changes the way atoms are grouped together.     He also created a list of elements, seen below.

Errors in his studies: 1. He thought the atoms were identical. 2. His system of atomic weight was not very accurate. 3. He gave oxygen an atomic weight of seven instead of eight.

Other things that were happening during Dalton's time was the 1804 journey of Lewis and Clark. ** Created by: Brittany, C.C., Courtney, and Markaile. **

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