Elements - Structure And Bonding
Main Points To Be Used In Answering A Past Paper Question:
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Down the group there is a change in structure from giant molecular to giant metallic and a change in bonding from covalent to metallic.
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From C to Ge elements exhibit a giant molecular structure.
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Sn and Pb exhibit a giant metallic lattice structure.
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From C to Ge bond length between group IV atoms increases and bond energy/strength decreases.
Main Points To Be Used In Answering A Past Paper Question:
- Down the group there is a change in structure from giant molecular to giant metallic and a change in bonding from covalent to metallic.
- From C to Ge elements exhibit a giant molecular structure.
- Sn and Pb exhibit a giant metallic lattice structure.
- From C to Ge bond length between group IV atoms increases and bond energy/strength decreases.
Elements - Electrical Conductivity
Trend: Going down the group there is a general increase in electrical conductivity.
Reason: Down the group there is a gradual increase in metallic character due to an increase in delocalisation of electrons throughout the structure.
Note: There is an increase in electrical conductivity from C(diamond) to Sn. There is a decrease from Sn to Pb which has never been addressed in the past papers. Hence we use the phrase "general increase" when talking about the trend in electrical conductivity down the group.
