Properties of Compounds - Ionic, Covalent and Metallic

1. Recap, we have learnt
2 types of bonds exist
between compounds
Covalent Bonds
- Electrons are shared
Ionic Bonds
- Electrons are Transferred

- Balancing charges

2. (D) Properties of Ionic Compounds:
3. made of crystals
4. have high melting points
5. often soluble in water
6. conduct electricity in water

3. They are crystalline solids
2D Image

4. Why do ionic compounds have high melting
points?
Opposite charges attract, forming strong ionic bonds.
Thus a lot of energy is needed to separate the ions.

5. Why do ionic compounds dissolve in water?
The electrons in H
2O molecule are not evenly spread.
One end of the molecule is slightly negative compared to
the other end.

6. •The water molecules
are attracted to the ions
and pull them from the
giant structure.
•The compound
dissolves.
•Its ions are now free to
move around  able to
conduct electricity.

7. Electrical Conductivity:
•Ionic compounds when solid do not conduct electricity.
•The ions are tightly held in place in the lattice structure and
are unable to carry charges.
•However, when molten or dissolved in water, they can
conduct electricity because the crystal lattice has broken
down and the ions can move.
Do covalent compounds dissolve
and conduct electricity too?

8. (D) Metallic Bonding
Metals generally have the following properties:
4.High melting and boiling points
5.Conduct electricity and heat
6.Hard and dense
7.Can be hammered into shapes (malleable)
8.Can be drawn out into wires (ductile)

9. Metal atoms (or ions) are held together by a sea of electrons.
Each metal atom gives up electrons from its outer shell
into the sea or cloud of electrons.

10. These free electrons explain how electricity can pass through
solid metals.

11. Lets Compare the 3 types of compounds –
Covalent, Ionic & Metallic
Watch the video and
answer these questions
Covalent Compound
= Naphthalene
Ionic Compound
= NaCl
Metallic Compound
= Tin

12. Questions : Copy these onto your notes
1.Which substance conducts electricity when
solid?
3.Which substance conducts when dissolved
in water?
5.Which substance does not dissolve in
water?

13. Summary
Today we have touched on
The properties of ionic compounds
Metallic bonding (sea of electrons)
Some differences between the 3 types of
compounds.