1. Simple molecular substances
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Water is an example of a simple molecular substance.
It is a small covalent compound containing a fixed number of atoms and bonds (e.g. H2O).

2. Comparing simple molecular substances
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In what ways are water molecules and methane molecules similar?
In what ways are they different?

3. Deducing Properties 21/09/2018
Use the following table to determine a set of common properties for simple molecular substances.
Aluminium oxide (Al2O3): Ionic compound/2040°C melting point/2977°C boiling point/Solid.
Titanium (element): Metallic bonding/1668°C melting point/3287°C boiling point/Solid.

4. Explaining the properties
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Explaining the properties
“When simple molecular substances melt or boil, it is the intermolecular forces that break not the covalent bonds”
Use the two statements to explain why simple molecular substances have low mp/bp and do not conduct electricity.
“Simple molecular substances are not charged molecules and do not form charged ions”

5. Explaining the properties
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“When simple molecular substances melt or boil, it is the intermolecular forces that break not the covalent bonds”
IMFs are much weaker than covalent bonds  require less energy to break.
This results in lower melting/boiling points.
This was observed in the data.

6. Explaining the properties
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Now do Qs on page…56
Electrical conductivity occurs as the results of charges flowing.
Free electrons or charged ions are required to carry electrical charge.
This is not possible with simple molecular substances.
“Simple molecular substances are not charged molecules and do not form charged ions”

7. Simple molecular vs. Giant covalent
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Simple molecular vs. Giant covalent C F G A B D E
Decide whether the above structures classify as either “simple molecular substances” or “giant covalent structure”.
Then make a list of differences and similarities between giant covalent structures and simples molecular substances. Use the table below to record these (leave plenty of space to add to this later).
Simple molecular substances vs. Giant covalent structures
Similarities
Differences

8. Properties of Giant Covalent Structures
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Now do Qs on page…57
Many atoms covalently bonded together
Due to there being…
Which are very strong and need lost of energy to break.
No fixed size – networks can be continuous
Very high melting and boiling points.
Do not conduct electricity – regardless of state of matter.
…but we can state ratios (e.g. SiO2)
Except Graphite: delocalised electrons

9. What similarities and differences are there between these molecules?
Allotropes of Carbon
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Allotropes: Structures in which the same element exists in different physical forms.
What similarities and differences are there between these molecules?
How might these similarities and differences affect their properties (e.g. melting points/conductivity)

10. Allotropes of Carbon 21/09/2018
Allotropes: Structures in which the same element exists in different physical forms.
Each made from only carbon atoms.
Carbon atoms arranged in different physical forms.
Graphite (Left) and Diamond (Right): Giant covalent structures.
Buckminsterfullerene (Centre): Not a giant covalent structure.

11. Allotropes of Carbon 21/09/2018
Allotropes: Structures in which the same element exists in different physical forms.
Each made from only carbon atoms.
Carbon atoms arranged in different physical forms.
Graphite (Left) and Diamond (Right): Giant covalent structures.
Buckminsterfullerene (Centre): Not a giant covalent structure.

12. Questions! Use the table (from page 108) to answer the questions below
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Questions! Use the table (from page 108) to answer the questions below

13. Conductivity: Electrical and thermal
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Metallic bonding: positive metal ions surrounded by a sea of delocalised electrons.
Delocalised electrons move freely around the metallic structure.
Able to carry heat energy and electrical charge!

14. Malleable/Ductile
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Metals can easily be shaped (pulled into wires, hammered into shapes, bent etc.)
This is due to their layers of atoms sliding over each other easily.
This can be very useful!
However, this can lead to metals not being strong enough for a whole range of jobs!
How could we stop these layers from sliding so easily?

15. Alloys 21/09/2018 Now do Qs on page…58-59
Alloy: a mixture of a metal with small amounts of other elements, usually, metals or carbon.
Added elements are of different sizes: layers now jam instead!
Think – Pair – Share!: List examples in which alloys could be more useful than the pure metal form.
Could have said: jewellery, construction, aircraft, cutlery.

16. Shape memory alloys
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Shape memory alloy: an alloy that can return to its original shape after being deformed.
Example: Nitinol (Nickel-titanium alloy).
Warming nitinol returns it to its original shape!

17. [Title]
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