Unit 6 (Chapter 12) notes: Covalent Bonds
Objectives:
 Compare and contrast ionic, covalent (polar and non-polar) and metallic bonds and compounds.
 Describe how a polar molecule is different from a non-polar molecule.
 Name molecular (covalently bonded) compounds given a formula.
 Write the formula for a molecular compound given the name.
Review Ionic Bonds:
 In an ionic bond, a ______________________ of electrons occurs. (give and take)
 Ionic bonds are classified as having an electronegativity difference greater than or equal to
_________.
 Ionic bonds are formed when ________ bond. The force holding the bond together is the
______________ attraction between the _____________ and the _________________.
 Ionic bonds usually involve the bonding of a ______________ and a ______________ (or
polyatomic).
Metallic Bonds:
 From the information on your table of bonds, is a metallic bond closer to an ionic or covalent
bond? Why?

The force holding a metallic bond together is the __________________ __________________.

How do the delocalized electrons explain the properties of metallic bonds?
Covalent Bonds:
 In a covalent bond a ___________________ of electrons occurs. An unequal sharing is
considered a _______________ covalent bond and an equal sharing is considered a
________________ covalent bond.
 Covalent bonds are classified as having an electronegativity difference less than ___________.
polar covalent: between ___________ and ___________.
non-polar covalent: less than or equal to _________.
 Covalent bonds are formed when _____________ ________ bond. The force holding the bond
together is the ______________ of ____________________ ________________.
 Covalent Bonds usually involve the bonding of two _________________.
 Covalently bonded compounds are referred to as a _____________ compounds, because a
____________ is formed.
Writing and Naming Molecular Compounds:
 The way we name molecular (covalently bonded) compounds is different (and easier!) than ionic
compounds.
 The first atom keeps its name and the second atom’s ending is changed to “-ide”
 Prefixes will be added depending on how many of each atom there is. If there is only one of the
first atom, the prefix “mono-“ is dropped.
 Because molecular compounds involve the bonding of neutral atoms, you do not have to
balance the charge like you did in writing ionic formulas.
Prefixes:
1 – mono2 – di3 – tri4 – tetra5 – penta6 – hexa7 – hepta8 – octa9 – nona10 – deca-
Examples:
Name:
BF3 _____________________________
H2O ____________________________
S2O5 ____________________________
CCl4 ____________________________
XeF6 ____________________________
Write the Formula:
carbon monoxide
________
carbon dioxide
________
disulfur heptachloride
________
pentoxide tetraiodide
________
*********************************************************************************
ionic compounds: usually a metal + non-metal or metal + polyatomic
molecular compounds: usually 2 non-metals
**********************************************************************************
Classify the following bonds as polar covalent or non-polar covalent. Draw the space filling model
and label which end will be δ+ (partially positive) and which end will be δ- (partially negative).
C-O
N-N
H2O
BrCl