1) Ionic bonds form when electrons are transferred from one atom to another, giving the atoms opposite charges and forming ions. 2) The atom that loses electrons becomes a positively charged cation, while the atom that gains electrons becomes a negatively charged anion. 3) Ionic bond formation requires one atom to have a low ionization potential and the other a high electron affinity, so there is an overall decrease in energy when electrons are transferred.

2. Electronic configuration of the inert gas
Inert
Element
ATOMIC No. Electronic configuration
K L M N O P
He 2 2
Ne 10 2 8
Ar 18 2 8 8
Kr 36 2 8 18 8
Xe 54 2 8 18 18 8
Rn 86 2 8 18 32 18 8

3. Chemical bond: Force of attraction between any two
atoms, in a molecule, to maintain the stability
Transfer of one or more electron
from one atom to other
Sharing of one, two or three pair
of electrons between two atom
Sharing of electrons are
contributed by only one of the
combining atom
Electrovalent/Ionic bond
Covalent/Molecular bond
Covalent/Dative bond

4. Electrovalent/Ionic bond

5. Na Na
Cl Cl
- e
Cation
+ e
+
-
Anion
Electropositive atom
Electronegative atom

6. • Ions: Any atom or group of atoms that bears one or more positive or
negative electrical charges.
• Cation: Positively charged ions
• Anion: Negatively charged ions
Ionic bond, also called electrovalent bond, type of linkage
formed from the electrostatic attraction between oppositely
charged ions in a chemical compound.
Such a bond forms when the valence (outermost)
electrons of one atom are transferred permanently to
another atom. The atom that loses the electrons becomes a
positively charged ion (cation), while the one that gains them
becomes a negatively charged ion (anion).

7. Conditions for formation of Ionic bond are:
(i) The atom which changes into cation should possess 1, 2 or 3
valency electrons. The other atom which changes into anion should
possess 5, 6 or 7 electrons in the valence shell.
(ii) A high difference of electronegativity of the two atoms is
necessary for the formation of an Ionic bond.
(iii) There must be an overall decrease in energy i.e., energy must be
released. For this an atom should have low value of Ionisation potential
and the other atom should have high value of electron affinity.
(iv) Higher the lattice energy, greater will be the case of forming an
ionic compound.