Download Covalent Bonding

Warm-Up #27 A. 40
1. Ionic bonds form between a metal and
another metal. T / F
2. A bond between two nonmetals is called
a covalent bond. T / F
3. Ionic compounds have a low melting
point. T / F
4. Draw the Lewis dot structure for F.
5. Draw the Lewis dot structure for Li.
Warm-Up # 28 A. 41
• Complete the chart
Warm-UP #29 Copy and Answer
1. Group 1 has two valence electrons. T / F
2. Group 13 has thirteen valence electrons.
T / F
3. Group 18 has 8 valence electrons. T / F
4. What is the Lewis dot structure for Be?
5. What is the Lewis dot structure for P?
Covalent Bonding
Remember…
• Ionic bonds forms
between metals and
nonmetals.
• An ionic bond
happens when one
atom transfers its
valence electron(s) to
another atom.
Covalent Bonding
• What are covalent bonds?
– A covalent bond forms when atoms share one or
more pairs of valence electrons.
– Covalent bonds form between a nonmetal and
another nonmetal.
How to Represent Covalent Bonds
• Let’s consider H2, the simplest molecule.
• What is the Lewis dot structure for
Hydrogen?
H•
hydrogen atom
• Use the Lewis dot structure to show two
Hydrogen atoms combining.
H•
hydrogen atom
+
•H
hydrogen atom
How to Represent Covalent Bonds Cont.
• What would the product of the two
Hydrogen atoms look like?
H •• H
molecule
• Use Lewishydrogen
dot structures
to show the
Shared
entire reaction
H•
hydrogen atom
+
•H
hydrogen atom
H •• H
pair of
electrons
hydrogen molecule
Covalent Bonding
• Show the reaction of two Fluorine atoms
combining to create F2.
••
•F •
•
••
atom
+
••
• F ••
••
atom
• •F•
•
••
• ••
•F
• •
••
molecule
or
• •F•- •F ••
•
•
•• ••
structural
formula
shared pair
Can atoms share more than one
pair of electrons?
• YES!!!
• Atoms sometimes share more than one pair of
electrons to attain 8 electrons.
• Double covalent bonds involve two shared pairs
of electrons.
Covalent Compounds
• Most items around you are covalently
bonded such as water, sugar, oxygen and
cellulose in wood
– What are some other covalently bonded
things?
• Properties of Covalent Compounds
– Brittle Solids
– Low melting and boiling points
Covalent Compounds Cont.
• Covalent compounds frequently involve more
than two atoms combining.
– Water, H2O
– Methane, CH4