1. Atomic Structure and the Periodic Table
Chapter 10 Notes

2. Chemical Symbols
Chemical symbol – an abbreviated way to write the name of an element. -example: Carbon – C Proton – positively charged particle found in the nucleus of an atom. Neutron – neutrally charged particle found in the nucleus of an atom. Atomic number – the number of protons in the nucleus of an atom.

3. The Electron Cloud
Electron cloud – cloud that surrounds the nucleus of an atom that describes the region in which an electron is most likely to be.
Example: students in a school

4. Energy Levels
You can represent the energy differences of the electrons by picturing the atom as having different energy levels.
Example: shelves of a refrigerator door (table 10-3)

5. Masses of Atoms
Mass number = the sum of the number of protons and the number of neutrons in the nucleus of an atom.
Number of neutrons = mass number – number of protons.

6. Isotopes
Atoms of the same element that have different numbers of neutrons.
See table 10-4 on pg. 279

7. Average atomic mass
Average atomic mass = the average mass of the mixture of an element’s isotopes.
Example: boron-11

8. In-class Assignment
Do pg. 281, 1-3