simple molecules lo: describe the properties of substances made from simple molecules. (d) explain...

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Simple moleculesLO:

Describe the properties of substances made from simple molecules. (D)

Explain how covalent bonds are strong, but simple molecules have low melting points. (C)

Explain why simple molecules have particular properties (B)

Explain the differences in properties of simple molecules which occurs even though covalent bonding is strong (A/A*)

Make these models

HCl

H2O

CH4

C2H6

CO2

CH3CH2OH

Carbon

Hydrogen

Oxygen

Chlorine

Single bond

Double bond

Covalent compounds

Water Sulphur

Ethanol

IodineWhat do these substances have that is similar ?

What tests for properties could you do ?

Covalent bonds are stronger than ionic bonds…..FACT !

Practical

WEAR GOGGLES

STAND UP

REPORT ALL SPILLS AND BREAKAGES

Using a boiling tube and a thermometer find out…

-The temperature that the wax melts at.

-The temperature that the water boils at.

-Record your results.

Conductivity demo

Wax

Ethanol

Ammonia

Say why covalent molecules do not conduct electricity

Covalent compounds do not conduct electricity because….There are no electrical charges to carry the electricity

Melting and Boiling

I said that covalent bonds are stronger than ionic.

If this is the case why do many covalent compounds have very low melting and boiling points ?

Covalent bonds are strong, but each molecule is separate to its neighbour.

The forces between each MOLECULE is very small.

There are weak intermolecular forces.

Make a statement

About covalent bonding.

The rest of the class will have to decide if it is true or false.

Write a Question

About anything to do with chemistry that we have done so far.

Simple ____________ do not conduct _____________ because there are no __________ on the molecule. They have very weak ___________ between molecules and are usually found as ___________ or gases. When they do form ____________ they are __________ and not __________. They do not dissolve in ____________ but can ___________ in other liquids.forces hard charges solids dissolve water molecules liquids electricity waxy

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