There are four types of solids depending on the bonding between particles: molecular, macromolecular, metallic, and ionic. Covalent bonding forms molecular solids like iodine and macromolecular solids like diamond. Metallic bonding results from delocalized electrons binding metal ions into a lattice, allowing metals to conduct electricity and heat well. Ionic bonding occurs between oppositely charged ions, forming ionic solids that are hard but brittle.

2. At the end of this lesson we will be able to
understand :-
Why an atom gets bonded with other atom or
atoms.
Different types of solids depending upon type of
bonding between their particles.
Properties of different solids.

3. Group zero elements
Element Electronic Behavior of
configuration atoms
2He4 2 Helium atoms
do not bond
10Ne20 2,8 Neon atoms do
not bond
18Ar40 2 ,8, 8 Argon atoms do
not bond

4. Argon: 18Ar40
Third shell : 8
electrons
Second shell : 8
electrons
First shell: 2electrons
Nucleus
Each shell is full .

5. Magnesium :12 Mg24
Third shell : 2 electrons
Second shell : 8 electrons
First shell ; 2 electrons
Nucleus
Outer shell not full : only 2 electrons in it

6. Now I am sure you can tell me
that why bonding takes place
between two atoms.
Press Enter to continue

7. Types of solids
Depending on the type of bonding solids
are of Four types –
 Molecular solids
 Macromolecular solids
 Metallic solids
 Ionic solids

8. Iodine : a molecular solid
I I
Two atoms of iodine
I I
Two atoms bonding together

9. I I
Two Iodine atoms

10. A covalent bond between two Iodine atoms is formed
I I I-I
An Iodine molecule

11. I I I I
I I I I
A Collection of iodine atoms Iodine molecules, full shells

12. Carbon (diamond) : a macromolecular solid
C C
C
C C
Carbon is in IV group –each atom has 4 outer shell electron

13. C C
C
C C
Central carbon atom now has a full outer shell

14. Carbon lattice
The whole lattice is held together by covalent bonds.
These are strong forces of attraction, so a considerable
amount of energy is needed to break up the lattice.

15. Lattice of iodine molecules
The forces of attraction between molecules is weak ,
however – they all have full shells – so lattice is easily
broken up.

16. Sodium : a metallic solid
sodium atom Na
Removed
sodium ion Na+ electron
11 protons, 11 electrons: neutral 11 protons, 10 electrons:+ charged

17. Metallic Bonding
repulsion
Metal ion attraction
- Delocalized electron

18. Force applied
Metals are malleable and ductile : they can be
bent , shaped and drawn into wires.

19. Metals conduct electricity well
delocalized electrons moving though the lattice carrying
negative charge

20. Metals conduct heat well
COLD END
HOT END
ELECTRONS ELECTRONS
MOVING QUICKLY MOVING SLOWLY

21. Salt : an ionic solid
atoms ions
+
Na
Na
-
Cl Cl

22. Electrovalent bond between cat ions and anions
cat ion
anion

24. Force applied
repel
Although ionic solids are hard , they are brittle. They
shatter when hit by a hammer.

25. electrode electrode
+ -
+ -
+
-
+
-
+
-
+
+ -
+ -
+ -
+ -
solvent particles

26. Summary
• Properties of a solid depend on the type of particle
in the lattice & the way in which they attract each
other in the lattice.
• There are three types of bonding – covalent
bonding, metallic bonding, ionic bonding .
• In all these bonding, the atoms achieve full electron
shells .
• An ion is a particle which has gained or lost
electrons, so is charged .