2. Properties
1)Covalent compounds generally have much
lower melting and boiling points than ionic
compounds.
2)Covalent compounds are soft and squishy
(compared to ionic compounds, anyway
On the other hand, covalent compounds have these
molecules which can very easily move around
each other, because there are no bonds between
them. As a result, covalent compounds are
frequently flexible rather than hard.
3. More Properties
3)Covalent compounds tend to be more
flammable than ionic compounds.
4)Covalent compounds don't conduct
electricity in water.
5)Covalent compounds aren't usually
very soluble in water.
4. USES OF COVALENT COMPOUNDS
1.Each and every kind of fuel and most of the
medicines that we use in our day to day life are
formed due to the formation of covalent bond
among the constituent elements of substances.
2.Most of the clothes that we wear consists of
covalent compounds only.
3.Most of the food materials that we use for
sustaining life are formed due to the formation of
covalent bonds only
.By the clear understanding of chemical bonding
we came to know the nature of every substance in
nature.
5. Molecular Compounds
In this chapter, you will learn about another
type of bond in which electrons are shared
Covalent Bonds are atoms held together by
SHARING electrons between NONMETALS
6.
7. Covalent Bonding
Remember that ionic compounds transfer
electrons in order to attain a noble gas
electron configuration
Covalent compounds form by sharing
electrons to attain a noble gas electron
configuration
Regardless of the type of bond, the Octet
Rule still must be obeyed (8 valence electrons)
8. Single Covalent Bond
A Single Covalent Bond consists of two atoms
held together by sharing 1 pair of electrons (2 e-)
10. Shared versus Unshared Electrons
A Shared Pair is a pair of valence electrons
that is shared between atoms
An Unshared Pair is a pair of valence
electrons that is not shared between atoms
11. Double Covalent Bonds
Sometimes atoms attain noble gas configuration
by sharing 2 or 3 pairs of electrons
A Double Covalent Bond is a bond that
involves 2 shared pairs of electrons (4 e-)
12. Triple Covalent Bond
A Triple Covalent Bond is a bond that
involves 3 shared pairs of electrons (6 e-)
14. Bond Dissociation Energy
Bond Dissociation Energy is the energy
required to break a bond between two atoms
● A large bond dissociation energy corresponds
to a strong bond which makes it unreactive
● Carbon has strong bonds, which makes carbon
compounds stable and unreactive
15. Polar Bonds and Molecules
There are two types of covalent bonds
■ Nonpolar Covalent Bonds (share equally)
■ Polar Covalent Bonds (share unequally)
16. Polar Covalent
•A Polar Covalent Bond is unequal sharing of
electrons between two atoms (HCl)
•In a polar covalent bond, one atom typically has a
negative charge, and the other atom has a positive charge
17. Nonpolar Covalent Bond
• A Nonpolar Covalent Bond is equal sharing of
electrons between two atoms (Cl2, N2, O2)
18.
19. Classification of Bonds
You can determine the type of bond between two
atoms by calculating the difference in
electronegativity values between the elements
Type of Bond Electronegativity
Difference
Nonpolar Covalent
Polar Covalent
Ionic
0 0.4
0.5 1.9
2.0 4.0
20. Attractions Between Molecules
Besides ionic, metallic, and covalent bonds,
there are also attractions between molecules
Intermolecular attractions are weaker than
ionic, covalent, and metallic bonds
There are 2 main types of attractions between
molecules: Van der Waals and Hydrogen