V. Valence Electrons

A. Valence Electrons Valence electrons – found in the OUTERMOST (highest) energy level (sometimes called a shell) Located in highest s and p sublevels These electrons are used for bonding Elements range from having 1 – 8 valence electrons – Example: Nitrogen: 1s 2 2s 2 2p 3 Nitrogen has = 5 valence electrons

B. Valence Electrons From Noble Gas Configurations PRACTICE:# Valence e- Na[Ne]3s 1 Mg[Ne]3s 2 Al[Ne]3s 2 3p 1 Ca[Ar]4s 2 Br[Ar]4s 2 3d 10 4p

C. Valence Electrons From Periodic Table

D. Lewis Dot Diagrams Lewis Dot Diagrams – way to visually represent valence electrons in an atom. Dots around element symbol = valence electrons Max of 8 electrons around symbol : OCTET RULE

2 nd Period Lewis Dot Diagrams Li ON Be FNe B C

Practice Write the Lewis Dot Diagram for the following elements – Krypton – Calcium – 1s 2 2s 2 2p 6 3s 2 3p 4 – [Ar] 4s 2 3d 10 4p 5 – Antimony (Sb)

Due by the END of Class! Write the Noble Gas Configuration, orbital diagram, and Lewis Dot Structures (valence electrons) for these elements: LiOSiPK SeSrIBaSn