Describe the three main types of bonding?
- Ionic bonding - occurs between a metal an a none metal. Electrons are transferred between two atoms to form ions - atoms with either a positive or negative charge. Ionic bonding occurs because of the strong electrostatic attraction between the oppositely charged ions. The ions form a lattice, an ionic compound. Ionic compound conduct electricity when molten or dissolved, have high melting points and are soluble. E.g. NaCl2) Covalent bonding - occurs between two none metals. Electron pair sharing. The covalent bond is very strong but most covalent compounds exist as compounds made up of lots of individual molecules. The atoms within the molecules are held together by the strong covalent bonds, the molecules are held together by weak intermolecular forces. This results in them having low boiling points and being electrical insulators. E.g. H2O. 3) Metallic bonding - occurs between two metals. The valence electrons of a metal are not localised around the atom but exist as a cloud of electrons around all the ion centres. The metal is held together by strong forces of attraction between the electron cloud and the ion centres. Metals have good thermal and electrical conductivity as a result of the delocalised electrons.
