SUMMARY - Descriptions IONIC Crystals Dissolve in water eg sodium chloride (salt) METALLIC Strong malleable solids Don’t dissolve eg copper SIMPLE MOLECULAR Usually Gases eg CO 2 , H 2 O GIANT MOLECULAR Hard strong solids Don’t dissolve eg diamond (graphite – special case) IONS ONLY IONS + FREE ELECTRONS MOLECULES ONLY ATOMS joined into GIANT MOLECULES
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SUMMARY - DescriptionsIONIC
CrystalsDissolve in water
eg sodium chloride (salt)
METALLICStrong malleable solids
Don’t dissolveeg copper
SIMPLE MOLECULARUsually Gases
eg CO2, H2O
GIANT MOLECULARHard strong solids
Don’t dissolveeg diamond
(graphite – special case)
IONS ONLY IONS +
FREE ELECTRONS
MOLECULES ONLY
ATOMS joined into
GIANT MOLECULE
S
SUMMARY - PROPERTIESStructure Property Reason
Ionic HIGH mpt/bpt
CONDUCT: Solid NO
Molten YES Dissolved YES
Strong bonds between IONS
Ions can’t move
Ions can move to carry current
Covalent –
Simple molecular
LOW mpt/ bpt (often gas at room temp). Soft when solid
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