2. 1) Chemical Bonds
 A) Metallic Bonds
a chemical bond characteristic
of metals, in which electrons are
shared between atoms and
move about in the crystal.

3. Metallic Bonding

4.  B) Ionic Bonds
Oppositely charged ions have a strong
mutual electrostatic attraction when
brought together, but, if brought too close,
the electron clouds repel each other. Thus,
a pair of mutually attracted ions will
maintain a certain distance from each
other. This distance is called the bond
length, and the electrostatic attraction of
the ions constitutes an ionic (or
electrovalent) bond.

5. Ionic bonds are very common and are
exemplified by table salt, in which a
sodium ion attracts a chloride ion to
form Na+Cl- or, as usually written, NaCl.
Calcium ions (Ca2+) and chloride ions
(Cl- ) combine in a one-to-two ratio to
form calcium chloride, CaCl2. The total
charge on each combination of ions,
NaCl and CaCl2, is neutral, or zero.

6.  Ionic Bonding: Salt

7.  C) Covalent Bonds
When two atoms share a pair of
electrons, they form a covalent bond.
When atoms bond covalently, they
form molecules. A molecule can be
made up of two or more atoms, all
joined with covalent bonds. Each atom
can share its electrons with one or
more other atoms. Some molecules
contain chains of thousands of
covalently bonded atoms.

8. Covalent Bond

9. 2) Types of Covalent Bonds
 A) Non-polar covalent bond
A covalent bond formed between two like
atoms is known as Non-polar bond. Since
difference of
electro negativity is zero therefore, both
atoms attract electron pair equally and no
charge appears on
any atom and the whole molecule becomes
neutral.

10.  Example:
H-H
Cl - Cl
F-F

11. b)Polar covalent bonds
A covalent bond formed between two
different atoms is known as Polar covalent
bond.
For example when a Covalent bond is
formed between H and Cl , it is polar in
nature because Cl is more electronegative
than H atom . Therefore, electron cloud is
shifted towards Cl atom. Due to this reason
a partial -ve charge appeared on Cl atom
and an equal +ve charge on H atom.

12.  Example

13.  C) Coordinated covalent bonds
A coordinate covalent bond is when two
atoms have a covalent bond where the two
electrons that are shared by the atoms in
the bond come from only one of the atoms.
This bond does not have any different
properties than a polar covalent bond it is
just named differently to show that the
electrons came from an atom with a lone
pair. This occurs when a Lewis base
donates electrons to a Lewis acid.

14. 3)Types of intermolecular forces
It is important to be able to
recognise whether the molecules in
a substance are polar or non-polar
because this will determine what
type of intermolecular forces there
are. This is important in explaining
the properties of the substance.

15. *Dispersion forces (London forces)
 Dispersion forces exist between all small
covalent molecules
 Electrons within the molecule momentarily
shift away from one side of the molecule,
setting up a momentary temporary dipole.
The attraction between the and of the
temporary dipoles is called the dispersion
force. This is an attractive force!
 Dispersion forces are stronger for larger
molecules and for straight chain molecules.

16.  Dispression forces of attraction

17.  *Dipole-Dipole forces
Dipole-dipole forces exist only between
polar molecules
 A dipole-dipole force is the attraction of
the part of one molecule and the part of a
neighbouring molecule.
 Dipole-dipole forces are stronger when
molecules are more polar. Polar molecules
contain polar bonds and are asymmetrical in
shape.