1. Atoms and the periodic Table Chapter 4

2. Atomic structure Atoms are: The building blocks of molecules. Definition-”unable to be divided”~Greek Our conceptual model based on John Daltons 1808 theory.

3. What is an atom? Made of protons, neutrons, and electrons. The center is called the nucleus. We think that electrons move around the nucleus in a mini-cloud. Protons (positive charge) Neutron (neutral or no charge) Electrons (negative charge)

4. Bohrs model Compares atoms to planets. 1913 Each planet would be a “layer” of electrons.

5. Periodic Table Groups similar elements together. Atomic number=the number of protons. Mass number=the number of protons+neutrons