Download 6.2 Covalent Bonds

A
covalent bond is a chemical
bond in which two atoms
share a pair of valence
electrons.
 Exists between two nonmetals.
Nonmetels share electrons with other
nonmetals to achieve a stable electron
configuration
 When the electrons are shared a
covalent bond forms between the two
atoms
 Each nonmetal must have 8 valence
electrons to reach stability


Neutral group of atoms that are joined
together by one or more covalent bonds.
› The hydrogen molecule is neutral because it
contains two protons (one from each atom) and
two electrons (one from each atom).
› A chemical formula can be used to describe the
molecules of an element as well as a compound.
The hydrogen element has the chemical formula
H2.
There are several ways to show a
covalent bond.
1. In the electron dot model, the bond is
shown by a pair of dots.
• Dots represent the element’s valence
electrons.
•
There are several ways to show a
covalent bond.
2. In the structural formula, the pair of dots
is replaced by a line.
F
F

There are several ways to show a covalent
bond.
3. The electron cloud and the space-filling
models show that orbitals of atoms overlap
when a covalent bond forms.
 Many
nonmetal
elements exist
as diatomic
molecules.
 Diatomic
means “two
atoms.”
 Determined
by how many PAIRS of
electrons two atoms share
› When two atoms share two pairs of
electrons, the bond is called a double
bond.
 Hydrogen + Oxygen
H
O
H
H
O
H

When two atoms share two pairs of
electrons, the bond is called a double
bond.
› Oxygen + Oxygen
O
O
O O
 When
two atoms share three pairs of
electrons, the bond is called a triple
bond.
› Nitrogen + Nitrogen
N
N
N
N