Ionic bonding occurs through the electrostatic attraction between oppositely charged ions. Cations form when metals lose electrons, while anions form when nonmetals gain electrons. Ionic bonds are usually seen between metals and nonmetals. Ionic crystals form ordered structures with ions packed together. Ionic crystals have high melting points, are hard, and conduct electricity when molten or dissolved due to the ions being able to move.

1. Ionic bonding
D.M K.M S.H I.S

2. Contents
Introduction: Learning Objectives
Cations and anions form molecules
Quiz
What is chemical bonding?
What is the nature of ionic bonds?
Aggregate states of matter
Ionic crystals and their physical properties

3. Introduction: Learning Objectives
2. Learn how charges of elements are determined
3. Revise how chemical formulas are defined
4. Understand which factors make matter gas, liquid or solid
1. Understand what is chemical bond, why and how it is formed
5. Learn what ionic crystals are and which properties they have

4. What is chemical bonding and how do atoms bond?
2 8 1
2 8
+
2 8 7
+ 1 e–
2 8 8
–
lost electron obtains electron
Electrostatic force
– 1 e–
To follow stable octet some elements, usually metals, loose
their valence electrons and some, usually non-metals, gain.
= atoms are binded
Na Cl
Chemical bonding – is a lasting attraction between atoms,
ions, or molecules that form chemical compounds (molecules).

5. Ionic bonding
Ionic bond – a chemical bond that is created through the electrostatic
attraction between oppositely charged ions (cations and anions).
Electrons completely pass from one atom to another
+
Electrostatic force
–
Ionic bond usually occurs between metals and non-metals: NaCl
Usually elements with high difference between electronegativities create ionic bond!
Between polyatomic ions there is also ionic bong: (NH4)+ - 𝐍𝐎𝟑
−
Li with EN = 0.98 F with EN = 3.98

6. Some representatives of cations
 The charges of the 1st, 2nd and 13th groups elements = the number of valence electrons:
Charges
1st group 2nd group 3rd group
Li+, Na+, K+, Rb+, Cs+ Be2+, Sr2+, Mg2+, Ca2+, Ba2+, Sr2+ Al3+
 The elements of d block (3 – 12 groups) can create different types of ions. Elements of d
block loose electrons from the last shell which is always ns2 (in some cases ns1).
Subsequently all of them besides some exceptions (29Cu & 47Ag) have minimum +2 charge.
Charges
d block elements
Ag+, Cu+ Cu2+, Fe2+, Ni2+, Cr2+, Zn2+ Fe3+, Cr3+

7. Some representatives of anions
 The charge of 15 – 17 groups elements = the number of electrons they need to
complete their electron shells, but with negative charge.
Charges
17th group 16th group 15th group
F–, Cl–, Br–, I– O2–, S2– N3–, P3–
 There are polyatomic ions:
Charges
–1 –2 –3
OH–, NO3
−
, HCO3
−
, HSO4
−
SO4
2−
, CO3
2−
, SO3
2−
PO4
3−

8. How to define chemical formula of ionic compounds?
 The charges of the ions are corresponded to their valences.
 You know how to define the chemical formula of compound
Alx
3+
(SO4
2−
)y
III II x ∙ III = y ∙ II
In compound XxYy valencyX∙intigerx = valencyY∙ intigery
x = 2; y = 3
Al2(SO4)3

9. Ionic crystals
Aggregate states of matter
Solid Liquid Gas
Physical condition of a matter depending on temperature and pressure
Have a certain shape and
volume
Keep volume, but not shape.
Shape surrounded volume.
Has ability to flow
Keep neither shape nor
volume. Fill the whole
volume of surrounding
Intermolecular forces (IMF)
attract molecules
Kinetic energy Ек
repel molecules
IMF >> Eк IMF > Eк IMF < Eк
Molecules are very close to
one another and do not
move, instead vibrate
Molecules are still close,
but can move and past one
another
Molecules are very far
from one another and move
fast & chaotically
Crystals are formed only in solid state of a matter. Prior to understand what crystals
and crystalline lattice are you must understand the states of a matter.

10. Ionic crystals Solid state
Amorphous Crystals
Chaotical placement of
molecules. No certain
melting temperature
Ordered placement
of molecules.
Ionic
Large ordered structures formed
by intramolecular electrostatic
attraction between oppositely
charged ions.
There are several
types of crystals and
ionic is one of them.

11. Physical properties of ionic crystals
 They are hard
 They have high melting and boiling temperatures
 They are soluble in water (and other polar substances)
 They do not conduct electricity in solid state
 They are good electrical conductors when melted or dissolved
Substance Tmelting (oC)
NaCl 801
CaF2 1418
MgO 2852
Polar compounds are those with distinct
regions of positive and negative charge
Polar compounds are easily dissolved in each
other and barely in non-polar compounds
Greater the difference between
electronegativities – greater the polarity
The ions in solid are strongly attached to one another and cannot flow or move
At high temperatures or when dissolved intramolecular forces that keep
ions together are broken, so now ions can move!

12. Thank You!