T2 bonding, structure and the properties of matter

electrostatic attraction between positive and negative ions relatively strong attraction

in a giant lattice regular structure that extends in all directions in a substance electrostatic attraction between positive and negative ions holds the structure together

high melting and boiling points (strong electrostatic forces between oppositely charged ions) don’t conduct electricity when solid (ions in fixed positions) conduct when molten or dissolved in water - ions are free to move

P: Na+ Mg2+ Al3+ Ca2+ Rb+ N: Cl- Br- SO2-4 No-3 OH- ionic compounds are electrically neutral

reaction of a metal with a non-metal electron transfer occurs - metal gives away its outer shell electrons to non-metal

shared pair of electrons between 2 atoms

don’t conduct electricity (no ions) small molecules weak intermolecular forces low melting and boiling points

increase causes melting/boiling points to increase as well (more energy needed to overcome these forces)

very large molecules with atoms linked by covalent bonds special type of polymers, melt/soften when heated, no bonds between polymer chains. Strong intermolecular forces ensure that the structure is solid at room temperature, forces are overcome with heating - polymer melts

solids, atoms covalently bonded together in a giant lattice high melting/boiling points - strong covalent bonds mostly don’t conduct electricity diamond, graphite, silicon dioxide

diamond fullerenes graphite nanotubes graphene

four, strong covalent bonds for each carbon atom very hard, strong bonds very high melting point doesn’t conduct

three covalent bonds for each carbon atom layers of hexagonal rings high melting points layers free to slide as weak intermolecular forces between layers, soft, can be used as lubricant conduct thermal and electricity due to one delocalised electron per each carbon atom

hollow shaped molecules based on hexagonal rings but may have 5/7 carbon rings C60 has spherical shape, simple molecular structure (buckminsterfullerene)

cylindrical fullerene with length to diameter ratio high tensile strength (strong bonds) conductivity (deloc electrons)

single layer of graphite

forces of attraction between delocalised electrons and nuclei of metal ions

high melting/boiling points (strong forces of attraction) good conductors of heat and electricity (delocalised electrons) malleable, soft (layers of atoms can slide over each other whilst maintaining the attraction forces)

mixtures of metal with other elements, usually metals different sizes of atoms distorts the layers so they can’t slide over each other, making them harder than pure metals

low boiling and melting points due to weak intermolecular forces between molecules poor conductivity when solid as no ions to conduct poor conductivity when molten as no ions mostly gases and liquids

high melting/boiling points due to giant lattice of ions with strong forces between oppositely charged ions poor conductivity when solid as ions can’t move good conductivity when molten as ions are free to move crystalline solids

high boiling/melting points due to many strong covalent bonds between atoms poor conductivity when solid in diamond and sand as electrons can’t move good in graphite as free delocalised electrons between layers can move poor conductivity when molten generally solids

high melting/boiling points as strong electrostatic forces between positive ions and delocalised electrons good conductivity when solid as delocalised electrons are free to move through the structure good conductivity when molten generally shiny metal solids

shows particles as spheres doesn’t take into account different sizes of particles no forces are shown spheres are shown as solid