This is a brief description of the historical contributions of two great scientists.

1. Dalton and Lavoisier A New Dawn for Chemistry:

2. Conservation of mass and atomic theory Dalton – Atomic Theory Lavoisier – Conservation of Mass

3. John Dalton’s new Atomic Theory Lavoisier’s Conservation of mass

4. Atomic Theory - 1 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.

5. Atomic theory - 2 All atoms of a given element are identical. Carbon Atoms

6. Atomic theory - 3 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.

7. Atomic theory - 4 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. Based on Lavoisier’s Law of Conservation of Mass

8. Atomic theory - 5 Elements are made of tiny particles called atoms. Atom – from the Greek word “atmos,” meaning “indivisible”

9. Video 9:09 – 33:23 http://teachertube.com/viewVideo.php?video_id=130153

10. Credits http://www.innovacorporate.com/Activated_Carbon_Powder_&_Granular.htm http://ircamera.as.arizona.edu/NatSci102/NatSci102/lectures/spectroscopy.htm http://www.3dchem.com/moremolecules.asp?ID=234&othername=dihydrogen%20monoxide http://teachertube.com/viewVideo.php?video_id=130153&title=Developing_Atomic_Concepts