What is the chemical bond?
The
force which holds the atom together in molecules or crystals forms is known as
a chemical bond. Ionic bonds and covalent are two types of chemical bonds.
There are some reasons why bonds are formed, such as some elements need to
complete their outermost shell this required to lead the formation of the
chemical bond. Atoms try to complete their octet in various ways, which is
mention below.
a)
By sharing electrons, b) by the gain of electrons c) by loss of electrons.
There
are two types of chemical bonds 1) ionic bond 2) covalent bond.
◘ Ionic
bond:
the bond is formed by the complete transfer of electrons. The ionic bond is
also called an electrovalent bond. The bonds are formed between two opposite charged
ions together is known as an ionic bond. For example, sodium contains one
electron in its valance shells, so it loses one electron and forms a sodium
ion. Similarly, chlorine has seven electrons in its valence shell. It gains one
electron to complete its octet and forms a chlorine ion. This way, the ionic
bond is formed between atoms.
◘ Covalent
bond:
The bond is formed by the mutual sharing of electrons between two atoms. The pair of electrons that participate in this type of
bonding is known as shared or bonding. The covalent bond is also known molecular
bond.
There are three types of covalent bonds, which are given below.
A single covalent bond,
Double covalent bond
Triple covalent bond.
◘ Single covalent
bond: The single covalent bond is formed
by sharing one electron between two atoms. It is denoted by a single line (—).
For example, H2 contains one electron in its
valance shell. They share only one electron and forms a single covalent bond.
H• •H or H—H
Some other examples of single covalent are Cl2, HCl,
and CH4
◘ Double covalent bond: The double covalent bond is formed by sharing two electrons
between two atoms. It is represented by two double lines (=).
For example: in carbon dioxide, carbon has six electrons in
its valance shell, and oxygen contains two electrons in its valance shell. They
share two electrons between atoms and formed a double covalent bond.
:
O: :C: :O: or O=C=O
Some other examples of double covalent are O2 and
C2H4
◘ Triple covalent
bond: The bond is formed by sharing of
three electrons between the molecules. It is denoted by three single lines (≡).
For example, nitrogen contains five electrons in its valance
shell, and they share three electrons between two atoms and formed a triple
covalent bond.
: N⋮ ⋮N: or N≡N
Other examples of triple covalent bonds are CO, CN-
and C2H2
There are two types of nature of covalent bond
1) polar covalent bond 2) Non-polar covalent bond.
◘ Polar
covalent bond: The polar covalent bond is formed between
two different atoms. In a polar covalent bond, one atom is slightly is positive,
and the other element is slightly negative. Examples of polar covalent bonds
are HCl, H2O, NH3, HF, etc.
◘ Non-polar
covalent bond: The Non-polar covalent bond is formed
between two similar atoms. In a non-polar covalent bond, particles contain exact
charges, which may be positive or negative.
Examples
of non-polar covalent are Cl2, H2, O2, N2
◘ Coordinate
Covalent Bond: The bond is formed by one-sided sharing of
a lone electron pair, known as a coordinate covalent bond. The coordinate bond
is formed between two, unlike atoms. It is also known as a dative bond. It is
represented by an arrow (→).
Example of ammonia
reacts with hydrogen ions to form an ammonium ion.
H H
│ │
H━ N━H +H+→ H━
N━H →H
↑
↑
Donor Acceptor
What is an intermolecular
force of attraction?
The force of attraction among the molecules of compounds is
known as the intermolecular force of attraction.
Examples; Dipole-Dipole attraction, Hydrogen bond, metallic
bond, and London force
What is an intramolecular force of attraction?
The force of attraction which holds unstable atoms in
molecules or crystals is known as the intramolecular force of attraction.
Examples: ionic bond and covalent bond.
