metallic bonding and structure l.o.: describe metallic bonding as the attraction of positive ions...
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Metallic bonding and structure
L.O.:Describe metallic bonding as the attraction of positive ions to delocalised electrons.
Describe giant metallic lattices.
The ‘sea of electrons’
Metallic bonding:o atoms are ionisedo Positive ions occupy fixed positions in a lattice.o The outer-shell electrons are delocalised
The metal is held together by the attraction between the positive ions and negative electrons.
Metals have high melting and boiling points. The have good electrical conductivity.
Structure of ionic compounds
L.O.:
Describe structures with ionic bonding as giant ionic lattices.
Sodium chloride ionic lattice
All ionic compounds exist as a giant ionic lattice in the solid state
Why is the mp of MgO higher than the mp of NaCl?
o The greater the charge, the stronger the electrostatic forces between the ions o and the greater the amount of energy required to break up the ionic lattice during melting
Ionic compounds are non-conductors of electricity when they are solids.
Ionic compounds are conductors of electricity when molten or dissolved in water.
Sodium and chloride ions surrounded by water molecules.
• Describe the structures of simple molecular lattices.
• Describe the structures of giant covalent lattices.
• Explain physical properties of covalent compounds.
Week 7
© Pearson Education Ltd 2008This document may have been altered from the original
Crystal structure of solid iodine
Week 7
© Pearson Education Ltd 2008This document may have been altered from the original
Week 7
© Pearson Education Ltd 2008This document may have been altered from the original
Different forces in iodine
Week 7
© Pearson Education Ltd 2008This document may have been altered from the original
Tetrahedral structure
Week 7
© Pearson Education Ltd 2008This document may have been altered from the original
Hexagonal layer structure
