1. Atoms, Bonding, and the Periodic Table
Chapter 5 sec 1
Mr. Sapalicio
Monterey Highlands Physical Science

2. Valence Electrons and Bonding
Valence electrons- Valence electrons are the electrons that are in the shell or energy level that is farthest from the nucleus
The number of valence electrons in an atom of an element determines many properties of an element, including the ways it bonds with other atoms.
WHAT?

3. Chemical Bonds and Stability
Atoms are more stable and less likely to react when they have 8 valence electrons
Atoms react in a way that makes each atom more stable
When bonds form, one of 2 things happens
The number of valence electrons increases to 8 or
The atom gives up its loosely held extra electrons

4. Electron Dot Diagrams H He Li Be

5. Valence Electrons and Bonding (cont.)
Chemical Bond- The force that holds atoms together O------O
When atoms bond electrons can be shared or transferred between atoms.
This change results in a chemical reaction.
 A chemical bond is the attraction caused by the electromagnetic force between opposing charges

6. How the Periodic Table works
Periods- start with 1 valence electron and end with 8
Groups 1, 2, give the number of valence electrons.
Groups 3-12 vary between 1, 2, or 3 valence electrons.
Inert gases- group 18, very unreactive, they don’t transfer electrons.

7. How the Periodic Table works
Semimetals- lie along the zigzag line between metals and nonmetals.
They have 3-6 valence electrons
Hydrogen-