62 | CHEMICAL BONDING
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CHEMICAL BONDING
, 63 | CHEMICAL BONDING
CHEMICAL BONDING
CHEMICAL BOND:
“A chemical bond is the force that holds two or more atoms, molecules or ions together”.
The properties of a sustance depend on the type of the chemical bond between its atoms.
The term chemical bond includes ionic, covalent, dative, metallic bonds, as well as intermolecular
forces, i.e. van der Waals forces.
However, being weak enough, van der Waals forces are usually not termed as pure chemical bonds.
In this chapter, we shall discuss the types of bonds in the light of electronegativity and its effect on the
nature of bonding, dipole moment, and polarity.
Then, the modern bonding theories such as VSEPR, VBT, Hybridization, and MOT will be discussed in
detail. The intermolecular forces, i.e. van der Waals forces will also be taken into account.
NaCl has ionic bond and is solid, but water is a covalent compound and liquid
LEWIS CONCEPT OF BONDING
According to Lewis concept, atoms make bonds to complete their outermost shells to have noble gas-like
configuration. This is mostly attained through the formation of an octet in the valence shell.
Ionic Bond
According to Lewis theory, an ionic bond is formed when one atom (low ionization energy) completely
transfers its electrons to another atom (high electron affinity).
Example: Sodium (NA) and Chlorine (Cl)
Sodium has the electronic configuration 2,8,1. It loses 1 electron to become Na⁺ (2,8) – like the noble gas
Neon.
Chlorine has the configuration 2,8,7. It gains 1 electron to become Cl⁻ (2,8,8) – like the noble gas
Argon.
These oppositely charged ions (Na⁺ and Cl⁻) are then strongly attracted to each other, forming an ionic bond in
NaCl (table salt).
Group 1 & 2 metals (like Na, CA) and Group 16 & 17 non-metals (like O, Cl).
Figure 3.1: Ionic bond formation between Na and Cl
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CHEMICAL BONDING
, 63 | CHEMICAL BONDING
CHEMICAL BONDING
CHEMICAL BOND:
“A chemical bond is the force that holds two or more atoms, molecules or ions together”.
The properties of a sustance depend on the type of the chemical bond between its atoms.
The term chemical bond includes ionic, covalent, dative, metallic bonds, as well as intermolecular
forces, i.e. van der Waals forces.
However, being weak enough, van der Waals forces are usually not termed as pure chemical bonds.
In this chapter, we shall discuss the types of bonds in the light of electronegativity and its effect on the
nature of bonding, dipole moment, and polarity.
Then, the modern bonding theories such as VSEPR, VBT, Hybridization, and MOT will be discussed in
detail. The intermolecular forces, i.e. van der Waals forces will also be taken into account.
NaCl has ionic bond and is solid, but water is a covalent compound and liquid
LEWIS CONCEPT OF BONDING
According to Lewis concept, atoms make bonds to complete their outermost shells to have noble gas-like
configuration. This is mostly attained through the formation of an octet in the valence shell.
Ionic Bond
According to Lewis theory, an ionic bond is formed when one atom (low ionization energy) completely
transfers its electrons to another atom (high electron affinity).
Example: Sodium (NA) and Chlorine (Cl)
Sodium has the electronic configuration 2,8,1. It loses 1 electron to become Na⁺ (2,8) – like the noble gas
Neon.
Chlorine has the configuration 2,8,7. It gains 1 electron to become Cl⁻ (2,8,8) – like the noble gas
Argon.
These oppositely charged ions (Na⁺ and Cl⁻) are then strongly attracted to each other, forming an ionic bond in
NaCl (table salt).
Group 1 & 2 metals (like Na, CA) and Group 16 & 17 non-metals (like O, Cl).
Figure 3.1: Ionic bond formation between Na and Cl
