John+Dalton

Biography of John Dalton John Dalton was born on September 6, 1766. He lived with his mother, father, brother, and sister. His early education came from his father.  Dalton later on became a teacher himself in Kendal with his successful cousin. While living in Kendal, Dalton kept a meteorological diary and published it in 1793. He worked at the Kendal up until 1793 when he moved to Manchester to partner with a blind philosopher which aided much of his scientific knowledge. Dalton became a teacher of mathematics and natural philosophy at the New College in Moseley Street, which we know as Manchester College, Oxford. In 1794 he was elected a member of the Manchester Literary and Philosophical Society. In just a few short weeks after election he wrote his first paper on Extraordinary Facts relating to the visions of colors. Dalton went on to write several other papers after Extraordinary Facts. Then, in 1800 he became a secretary of the society. Although Dalton made several interesting experiments, his most important ideas were dealing with Atomic Theory. Many of Dalton's ideas were gathered from other chemists such as Lavoiser and Higgins. However, he was the first to put the ideas together into the Atomic Theory, which was undoubtedly his greatest achievement. Dalton ended up contributing 116 memoirs to the Manchester Literary and Philosophical Society. He became president of that foundation in 1817 and remained president until his death in 1844.

Proposed Atomic Theory
 * chemical elements are made of atoms
 * 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

Atomic Model In an attempt to explain how and why elements would combine with one another in fixed ratios and sometimes also in multiples of those ratios, Dalton formulated his atomic theory. He his atomic theory by research from other scientists along with his own research. Dalton came up with a model that had these characteristics:
 * Spherical
 * Solid (like a marble)
 * No substructure

 <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 120%;"> <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 130%;">Dalton's model was done in about 1800. Many things were missing from it. He thought the entire atom was a solid structure with no substructure. He also believed that it was completely solid inside like a marble.

<span style="color: #004af5; font-family: Tahoma,Geneva,sans-serif; font-size: 140%;">Negatives
 * <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 120%;">The model was solid, and could not be labeled with protons, neutrons, or electrons for they had not been discovered,
 * <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 120%;">There was no substructure in the atom.

<span style="color: #004af5; font-family: Tahoma,Geneva,sans-serif; font-size: 140%;">Positives
 * <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 120%;">This model led to many more ideas and models that were closer to being correct.
 * <span style="font-family: Tahoma,Geneva,sans-serif; font-size: 120%;">This model led to the discovery of the nucleus, protons, electrons, and neutrons.