John DaltonBy: Loren Goldman and Shelby DolanHonors Chemistry, Period 5

Background• Born: in Cumberland, England• Educated: in Quaker’s school in Eaglesfield• Dalton had a teaching position in Manchester• Best Known As: The weather pioneer

who advocated atomic theory• Died: 27 July 1844

Accomplishments

•Dalton discovered the partial pressure of gases• John Dalton developed atomic theory; his theory (1805) accounts for the law of conservation of mass, law of definite proportions and law of multiple proportions; produced the first table of atomic weights; colorblind and mostly self-taught.

Dalton’s model of atom•He believed that the atoms were tiny, indivisible, indestructible particles, and that each one had a certain mass, size, and chemical behavior that was determined by what kind of element they were.

Improvements for Dalton’s Model• John Dalton’s model of the atom was improved in the sense that many more discoveries about the atom were made, and as time went on, technology improved so we were then able to see that the atom actually has more components that just what Dalton observed. Atoms actually have shells, sub-shells etc. In addition to a nucleus, protons, electrons, and neutrons.

IMPROVED!

A Brief History of the Atomic Theory!

400 BC-350 BCAristotle, Greece - started the method of gathering scientific facts, which began as the basis for all scientific work.

John Dalton (1803), England - formed the atomic theory, which states that all matter is composed of tiny, indestructible particles called atoms that are all alike and have the same atomic weight. 

Albert Einstein (1905), Germany - stated that light was made up of different particles that, in addition to wavelike behavior, demonstrate certain properties unique to particles.  He also brought forth the theory of relativity.

Murray Gell-Mann and George Zweig (1964), USA - brought forth the idea of "quarks", little bits of matter which when used kind of like building blocks, serve to explain some complex chemical substances

** Only some, out of many stated (Most important ones).

Dalton’s Atomic Theory• Up until Dalton’s time the atom was only

considered to a philosophical construct passed down by the ancient Greeks.

• Dalton’s Theory:All matter is composed of atoms

Atoms cannot be made or destroyedAll atoms of the same element are

identicalDifferent elements have different types of

atomsChemical reactions occur when atoms are

rearrangedCompounds are formed from atoms of the

constituent elements.**Dalton was mostly a theorist, and did

not do any experiments!!

How theory fits with improvements

• It was noted that atoms can only be destroyed by only nuclear reactions not chemical reactions.

• Also there are different kinds of different masses, which are known as isotopes but still have the same chemical property as their element.

• we now know that atoms can be subdivided into protons, electrons, and neutrons. We'll get to that later though

• Dalton also imagined that in nature atoms always come in single groups, which we know is false too- most gases, like hydrogen and oxygen, are diatomic and are found in nature as a molecule of 2 atoms.

•Works Cited• "John Dalton." Chemical Heritage, Web. 7 Nov 2010.

<http://chemicalheritage.net/discover/chemistry-in-history/themes/the-path-to-the-periodic-table/dalton.aspx>.

• Francis, Eden. "Dalton's Atomic Theory." 2002. Web. 7 Nov 2010. <http://dl.clackamas.edu/ch104-04/dalton's.htm>.

• Blamire, John. "History of Chemistry." Science at a Distance. 2002. Web. 7 Nov 2010. <http://www.brooklyn.cuny.edu/bc/ahp/FonF/Dalton.html

• D. Leon, N. "Dalton's Atomic Theory." Web. 7 Nov 2010. <http://www.iun.edu/~cpanhd/C101webnotes/composition

• Jessa, Tega. "John Dalton's Atomic Model." 24 August 2009. Web. 7 Nov 2010. <http://www.universetoday.com/38169/john-daltons-atomic-model/>.