1. C2 Unit 1
Bonding

2. Learning Outcomes By the end of the lesson you ……be able to:
Must (Grade E/F): State what ionic bonding is.
Should (Grade C/D):
Could (Grade B/C):

3. Starter What are the chemical symbols for: Calcium Oxygen Sodium Iron
Copper
Carbon

4. What is a compound?
A substance formed when two or more elements chemically combine.
Can you give any examples?

5. What do we mean by chemically combined?
Involves either transferring or sharing of electrons in the highest occupied energy levels (shells) of atoms in order to achieve the electronic structure of a noble gas.

6. Full electron shells
Each shell has a maximum number of electrons that it can hold. Electrons will fill the shells nearest the nucleus first.
2nd shell holds a maximum of 8 electrons
1st shell holds a maximum of 2 electrons
3rd shell holds a maximum of 8 electrons
Atoms of noble gases have completely full outer shells. This makes them very unreactive or stable.

7. Ions
An ion is formed when an atom gains or loses electrons and becomes charged: + -
The electron is negatively charged
The proton is positively charged + +
If we “take away” the electron we’re left with just a positive charge:
This is called an ion.

8. Example Ions Hydroxide - OH- Cations Anions Sodium – Na+
Magnesium – Mg2+
Iron – Fe3+
Copper – Cu2+
Anions
Chloride – Cl-
Sulphate – SO42-
Carbonate – CO32-
Oxide – O2-
Hydroxide - OH-
All compounds have no overall charge. Can you therefore write down the formula of:
Sodium chloride
Magnesium chloride
Copper oxide
Iron Oxide (Kind of tricky!)
Barium Hydroxide (Very tricky!)

9. How to represent ionic bonding in an exam.
This is called an electrostatic attraction.
Ionic compounds have high melting points because of this attraction.
To melt this compound you would require a temperature of 801 degrees celcius.

10. Now apply knowledge to worksheet.

11. TRUE OR FALSE Answer the following questions T or F:
An ion is formed when an atom gains or losses electrons.
An example of a cation is sulphate SO42-.
A positive metal ion is formed when electrons are lost from the metal atom.
Ionic bonding is between a positive metal ion called a cation and a negative non-metal ion called an anion. It is the electrostatic attraction between these two ions.
5. Properties of ionic compounds are that they have low melting points, non-conductors of electricity when molten. T F T T F

12. Common ions bingo

13. Group 1 – The Alkali Metals
Watch the demo.
Write down your observations.
Write down the chemical reactions (word and symbol)

14. Group 7 – The Halogens

15. Group 1 and 7 elements react with each other.
Can you explain why?

16. Practical: Making ionic compounds
Substance
Appearance Before
Appearance after
Magnesium
Copper
Iron
Calcium reacts with oxygen in air to form calcium oxide.
Calcium + oxygen → calcium oxide
Ca O → CaO
Write the word and symbol equations for what is formed with the elements above.

17. Aluminium Oxide Structure