John Dalton’s Atomic Theory

1. John Dalton’s Atomic Theory Ryan Templeton, Sam Sanavi

2. Photos of Dalton

3. Who is John Dalton? • Born September 6, 1766, in Eaglesfield, England • Died July 26, 1844 in Manchester, England • Religious man, he was a Quaker, kept him from his fame • Teacher at the age of twelve, principal 5 years later • Professor at New College in Manchester

4. Studies • First got into meteorology • Researched color blindness which he had • Through his interests in atmospheric pressure he was led to gases • Studied gases and came up with his atomic theory

5. Dalton’s Atomic Theory • Dalton revised Democritus’s atomic law through experimental trial. • Believed of extremely small particles known as “atoms”. • Atoms are identical in means of mass, chemistry, size, and mass. • Atoms cannot be created, divided, or destroyed. • Different atoms combine to form compounds. • In chemical reactions, atoms are separated, combined, or rearranged.

6. Compared to Democritus’ theory. • Dalton’s atomic theory was a revised version of Democritus’ theory. • Democritus believed of small objects holding mass together known as Atoms. • Dalton and Democritus believed atoms were indivisible and invincible. • Dalton thought all atoms were one size, Democritus said all were different. • Democritus believed that physical traits of an object were caused by size and movement of atoms; Dalton did not believe this.

7. Compared to todays theory. • Dalton’s theory was technically valid, but in comparison to modern atomic theory, it was a bit off. • We know that atoms can be destroyed by nuclear reactions but not chemical reactions. • We also know that not all atoms are the same. Atoms can differ by factors such as mass thus making Isotopes.

8. Conclusion • Dalton’s atomic theory was a necessary and imperative study in science that showed the true make up of matter. • Even though some of his theories are wrong, it can’t be said that his work was not needed. • His theory holds theoretical foundation in science.

9. Websites to look at • http://www.biography.com/people/john-dalton-9265201 • http://www.iun.edu/~cpanhd/C101webnotes/composition/dalton.html