1. IONIC & COVALENT BONDING
THE OCTET RULE

2. Octet Rule
Atoms bond in order to achieve an electron configuration that is the same as the electron configuration of a noble gas
Ie. They have 8 electrons in their filled outer energy level (except He)

3. Chemical Bond
The force of attraction between two atoms or ions.

4. IONIC BONDING
Some elements tend to gain electron(s) readily while others tend to lose electron(s) (low I.E.)
When an active element (metal) reacts with an active non-metal), electrons are transferred from the metal to the non-metal. Atoms of the non-metal become anions while the metals become cations. These ions are attracted to each other by electrostatic forces.

5. Electrostatic Forces
Attraction between oppositely charged particles.

6. Ionic Bond
The type of chemical bond resulting from the electrostatic force of attraction between oppositely charged ions (as formed when metallic atoms transfer electrons to non-metallic atoms).

7. Example: electron dot formula to show the formation of the ionic compound NaCl  sodium chloride  table salt

8. Formation of Cation sodium atom Na sodium ion Na+ 11p+ 11p+ e- e- e-
loss of
one valence
electron
11p+ e- e- e- e- e- e-

9. Formation of Anion chlorine atom Cl chloride ion Cl1- 17p+ 17p+ e- e-
gain of
one valence
electron
17p+ e- e- e- e- e- e- e- e- e- e-

10. Formation of Ionic Bond
chloride ion
Cl1-
17p+ e-
sodium ion
Na+
11p+ e- e- e-

11. IONIC BONDING: Formation of Magnesium ChlorideCl Cl
Mg2+ Mg
Mg2+ Cl Cl
Loses 2e- Each gains 1e One magnesium ion Two chloride ions
Mg Cl1-
[(2+) (1-) = 0]
MgCl magnesium chloride

12. Ionic Bonding Na Cl

13. Ionic Bonding
Na+
Cl-

14. Ionic Bonding
All the electrons must be accounted for Ca P

15. Ionic Bonding Ca P

16. Ionic Bonding
Ca2+ P

17. Ionic Bonding
Ca2+ P Ca

18. Ionic Bonding
Ca2+
P 3- Ca

19. Ionic Bonding
Ca2+
P 3- Ca P

20. Ionic Bonding
Ca2+
P 3-
Ca2+ P

21. Ionic Bonding Ca
Ca2+
P 3-
Ca2+ P

22. Ionic Bonding Ca
Ca2+
P 3-
Ca2+ P

23. Ionic Bonding
Ca2+
Ca2+
P 3-
Ca2+
P 3-

24. Ionic Bonding
= Ca3P2
Formula Unit
Calcium Phosphide

25. Ionic Compound
A pure substance composed of positively charged ions and negatively charged ions in a fixed ratio

26. Classwork problems (a)
Show the bonding between the following
Magnesium and Oxygen
Potassium and Chlorine
Calcium and Fluorine
Lithium and Nitrogen
Aluminum and Fluorine

27. Homework problems These are slightly harder Magnesium and Phosphorus
Beryllium and Nitrogen
Calcium and Sulphur
Magnesium and Nitrogen
Aluminum and Oxygen

28. Ionic Bonding

29. Crystalline structure
i.e. Crystal lattice structure
 the rigid arrangement of ions
Solution animation

30. What happens when only non-metal elements are involved? . . . . . . . .
COVALENT BONDING