9.08.7 KEYWORDS

· Molecule - small group of atoms covalently bonded together (limited number of atoms unlike a lattice)

· Covalent Bond – strong electrostatic attraction between a shared pair of electrons and two nucleuses

· Double covalent bonds – strong electrostatic attraction between two shared pairs of electrons and two nucleuses

· Treble covalent bonds – strong electrostatic attraction between three shared pairs of electrons and two nucleuses

· Intermolecular forces – weak forces between molecules (ie from one molecule to another molecule)

· Molecular Formula – the formula that counts all the atoms in the molecule

· Graphite –Lattice of Carbon in sheets, conducts electricity (delocalised electrons), very soft. 3 bonds per atom, layers form in hexagons.

· Diamond –Lattice of Carbon bonded tetrahedrally with 4 bonds per atom. Insulator (no delocalised electrons). Very hard.

· Silica – Silicon Dioxide (SiO₂) – lattice structure and properties similar to diamond.

· Graphene – single sheet of Graphite, flexible, strong, conducts.

· Fullerenes – other forms of Carbon including “buckyballs” and nanotubes. Not lattices!

· Buckminsterfullerene – The basic Buckyball (C₆₀)

· Delocalised - able to move