H H N H Bond indicated by an arrow No charged particles + Power of an atom to attract the electron density in a covalent bond Strong H Shared pair of electrons A shared pair of electrons where both electrons are supplied by one atom Coordinate (dative covalent) bond Covalent bonds Intermolecular forces Permanent dipole-dipole forces Polar covalent bonds can cause a permanent dipole Uneven electron distribution produces a polar covalent bond Electronegativity Bond polarity Covalent Bonding 1.3 BONDING Do not conduct Contain a fixed number of atoms covalently bonded together Weakest Hydrogen bonds Strongest Influences low density of ice https://bit.ly/pmt-edu Strong covalent bonds between atoms Giant structure Shapes Induced dipole-dipole forces Low melting and boiling points Very high melting points Molecular structures Macromolecular structures Weak intermolecular forces E.g. diamond, graphite, silicon dioxide Shapes and bond angles of simple molecules and ions Molecules/ions with up to 6 electron pairs Electron pair repulsion VSEPR principles AQA https://bit.ly/pmt-cc https://bit.ly/pmt-cc Metal loses electron(s), non-metal gains electron(s) Electrostatic attraction between oppositely charged ions Giant Ionic Lattice Structure 1.3 BONDING: IONIC BONDING Properties Conduct electricity when molten or aqueous E.g. SO42-, OH-, NO3-, NH4+ Formulas of Common Ions High melting and boiling points Very strong electrostatic forces between ions Lots of energy needed to overcome forces Ions are free to move to carry charge AQA https://bit.ly/pmt-edu https://bit.ly/pmt-cc https://bit.ly/pmt-cc Easily separated Positive metal ions held in a sea of delocalised electrons Giant Structure 1.3 BONDING: METALLIC BONDING Strong metallic bonds Good conductors Delocalised electrons carry charge Properties High melting points Malleable Atoms arranged in a regular layers which can slide over each other https://bit.ly/pmt-edu AQA https://bit.ly/pmt-cc https://bit.ly/pmt-cc