Name _________________________________________________
___ 4.1 Chemical Bonding Notes____________________________________
A chemical bond is:
Bonding between atoms occurs because:
There are 3 types of bonding:
a.
b.
c.
____________________________________________________________________
Ionic bonding
Consider atoms of sodium and chlorine.
Sodium atom
Chlorine atom
Sodium ion Na1+
Chlorine ion Cl1-
____________________________________________________________________
Covalent bonding
In many cases electrons do not completely transfer from one atom to another. The
electrons between atoms are shared. Consider two hydrogen atoms.
Hydrogen atom
Hydrogen atom
NONPOLAR or PURE covalent bond is when:
A POLAR covalent bond is when:
Hydrogen atom
Chlorine atom
We use electronegativities to determine whether we have an ionic, polar covalent or
nonpolar covalent bond.
Electronegativity is defined as:
Look at the periodic table for electronegativity values. Subtract to get the difference.
If the difference is:
1.7 and higher
_________________bond
0.3 to 1.7
_________________bond
0.0 to 0.3
_________________bond
What type of bond will occur between iodine and the following elements: cesium,
iron, and sulfur?
The electronegativities of each are:
Iodine _______
Cesium _______
Iron _______
Bonding between Iodine Electronegativity
and
difference
Cesium
Iron
Sulfur
Sulfur _______
Bond type
More negative
atom
Determine the type of bond formed between the following pairs.
Bonding
between
Li & Cl
S & O
Ca & Br
P & H
Si & Cl
S & Br
Electronegativity
difference
Bond type
More negative atom