4_04_S_DianaMesser

Atomic theory

John Dalton 
Eaglesfield Cumbria, United Kingdom
Born September 6, 1766
Passed: July 27, 1844
(in Manchester, United Kingdom
78 Years old
Awards? Royal Award
Nationality? English, British
 Child of: Joseph Dalton & Deborah Greenup

• Were there experiences in his life that led to his interest in science and the study of the atom?

       The Success from birth has Dalton riding on the edge of his seat. Growing up Dalton was color blind, along with his brother. His early years as a scientist he placed a theory that colorblindness must be hereditary. Proving his theory true when he did a genetic analysis of his own eye tissue revealing to himself that he was missing the photoreceptor for the color green. Noticing that he had a form of red-green colorblindness, Leading to the name Daltonism. One interest led to another and soon became fascinated with with atmospheric pressures leading to the examination of gasses. In the early 1800's Dalton outsmarted others by studying the nature and chemical makeup of air, proving that it was a mechanical system composed
of small individual particles that used pressure applied by each gas one by one. 
In 1803 Humphry Davy, a Cornish chemist, had gotten skeptical about Dalton's
law until Dalton explained to Humphry the significance of the law and why the
other scientist are mistaken.  Also during the 1800's Dalton proposed a law of
thermal expansion that was to show the heating and cooling reaction of gases
to expansion and compression. Becoming famous for the additional study along
with all of the other ones. 

• Defend his work on the atom and its contribution to the modern atomic model.

John Dalton's interest in gases led his mind to propose that every form of matter ( solid, liquid, or gas) was also made up of tiny individual particles. seeking further in depth with his new theory, readdressing atomic weight in a published book "A New System of Chemical Philosophy" in 1808.... He mentioned that his belief lays with the atoms of different elements could be identified by the varying atomic weights. Dalton was the first scientist to explain the behavior in a measurement form. He also uncovered the fact that atoms cannot be created nor destroyed. 
I defend John Daltons atomic theory                                                           because the information gather proves he is correct. During this time,                                                         Dalton used the information gathered by studying just one of the states of                                                             matter. Making theories and proving them right each time, Dalton has                                                                    brought to light for many other scientist in the long run.  Atom's used in                                                     his atomic model helped improve and give a base for the modern model. 

• Point out which contributions are present in the modern atomic model and which were eventually disproven and thus are not part of the modern model.

Sadly, Dalton's work was not all correct. It was proven by more than 5 other scientist that he is wrong. The last scientists (being responsible for the most modern model.)  Has proven that the nucleus (center of the atom) is made up of protons and neutrons and is circled by electrons.  In the modern model it is still proven that matter cannot be created nor destroyed and Atoms are made up of tiny individual particles. Where he went wrong is that when all matter is not up of atoms and all atoms of a given element are identical in mass and properties. many scientist have debated on these subjects because all of them think that they have found evidence to help prove there point. Overall, Dalton's theories are accurate due to the information he had at the time, As well as his other success with the discovery of hereditary blindness that is still to this day called Daltonism.