Year 8 Science
Mix and Match
Aim: To represent the molecules of a number of different substances that
contain some or all of the elements; carbon, hydrogen and oxygen.
Carbon
(4 bonds)
Oxygen
(2 bonds)
Hydrogen
(1 bond)
Put a key on your paper, similar to that above, to indicate what each shape
represents.
For each of the substances below write:
i)
Name
ii)
Chemical Formula
iii)
Element or compound?
iv)
Use and Description
v)
Model of molecule (showing all bonds)
Atoms per molecule
Name
Carbon
Hydrogen
Oxygen
carbon dioxide (CO2)
1
0
2
hydrogen gas (H2)
0
2
0
Water (H2O)
0
2
1
oxygen gas
0
0
2
hydrogen peroxide (in hair bleach)
0
2
2
methane (natural gas)
1
4
0
3
8
0
2
6
1
8
18
0
Propane (gas for barbeques)
ethanol (alcohol)
octane in petrol
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These molecules are quite difficult to construct. Start by joining the carbon atoms
together in a chain with single bonds and then add the other atoms onto the carbon
atoms.
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