Notes #1: Covalent Bonding/ Lewis Dot Structures WCHS Chemistry NEED PERIODIC TABLE & A PENCIL!! QUIZ THURSDAY!

QUICK REVIEW! Valence Electrons = Outermost electrons! How to know how many…? GROUP NUMBER! Octet Rule = Atoms are most stable when surrounded by 8 valence electrons! Exceptions? H and He only have 2 What is an ion…? Charged atom! Write the formula for Sodium Oxide Na2O

IONIC BONDS Electrons are gained or lost so opposite charges attract Charges must add up to be NEUTRAL! Typically involves a metal and a nonmetal Ex: NaCl, AlBr , MgF, KS, CaO, LiBr

What about something like... -1 -1 Cl Cl Cl2 7 v.e. 7 v.e. Covalent Bonding Involves the sharing of e- Typically only involves NONMETALS ****Hydrogen IS a nonmetal. Only wants 2 v.e.! 1s2 Ex: CO2 H2O O2 N2

LEWIS DOT STRUCTURES: SINGLE ELEMENTS Show an atom’s valence electrons! Rules for a single element: 1. Fill each side one at a time 2. Maximum of 2 e- on each side This can change ONLY when bonding!!!!! K Se Ne O Br P Al Mg

LEWIS DOT STRUCTURES: COVALENT BONDS Start with the element that wants the most e- Be prepared to move e- around to line up with others for sharing!!! Circle ALL of the e- for EACH element! They should have 8 (or 2) and line up

Cl2 HCl

CH4 O2

N2