1. Chemistry Topic: Chemical Bonding

2. Chemical Bonding

3. Introduction What will happen when two magnets are put together? Why?
MAGNETIC FORCE causes the 2 magnets to stick together.

4. Bonding ELECTROSTATIC FORCE causes 2 atoms to join together.
The forces between 2 atoms are called BONDING.

5. Types of Bonding

6. Ionic Bond What is the chemical formula of sodium chloride? NaCl
Is NaCl neutral or a charge carrier?
Neutral

7. Ionic Bond (cont’d) What type of particles are present in NaCl? Ions
Are they neutral or charged?
Charged

8. Ionic Bond (cont’d) Which is positively / negatively charged?
Sodium ion, Na+, — positive
Chloride ion, Cl–, — negative

9. Definition of an Ionic Bond
An IONIC BOND is the strong non-directional electrostatic force of attraction between oppositely charged ions.
A pure ionic bond is formed by the COMPLETE transfer of one or more electrons from one atom to another.

10. Electron Transfer in NaCl
Na is a metal, Cl is a non-metal.
Generally, the electrons are transferred from a metal to a non-metal, i.e. from Na to Cl.
Why?

11. Electronic Configuration of Na
What is the electronic configuration of Na?
(2,8,1)
It tends to lose ONE electron to make it stable.

12. Sodium Ion
Losing one electron

13. Electronic Configuration of Cl
What is the electronic configuration of Cl?
(2,8,7)
It tends to gain ONE electron to make it stable.

14. Chloride Ion
Gaining one electron

15. Electron Diagram of NaCl
The electron is transferred from sodium atom to chlorine atom.
It is also called an electron ‘dot/cross’ diagram (or simply electron diagram)
Simplified notation

16. Another Example Let’s consider another example, magnesium fluoride.
What is the chemical formula of magnesium fluoride?
MgF2

17. Another Example (cont’d)
Mg loses 2 electrons.
F gains 1 electron.

18. Another Example (cont’d)
How many atoms of Mg and F are involved in this electron transfer process?
1 Mg atom, 2 F atoms
So, totally 3 atoms are involved in this process.

19. Magnesium Fluoride MgF2
Prediction the electron diagram of MgF2

20. Homework Draw the electronic diagram of the following compounds.
Potassium chloride
Magnesium bromide
Aluminum oxide

21. ~ ~