Covalent bonding

• Covalent bonds

  Bonds between two non metals
• Description for a covalent bond

  Electrostatic attraction between a shared pair of electrons and the nuclei of the 2 bonded atoms

  Formed when 2 atoms share electrons to gain a full outer shell of electrons
• How many electrons are shared in each covalent bond

  2 electrons
• Double bond

  2 covalent bonds between the same atoms meaning there are 4 electrons being shared in total
• Way of drawing a covalent bond

  Dot and cross diagrams

  Displayed formula

  3D models
• 3 types of substances covalent bonds can make

  Polymers

  Giant covalent structures

  Simple molecular substances
• Are covalent bonds or intermolecular forces stronger

  Covalent bonds are much stronger
• Polymer

  Large molecule made up of lots of smaller units called monomers
• Giant covalent structure

  Structure in which all the atoms are bonded to each we other by strong covalent bonds
• 3 examples of a giant covalent structure

  Diamond

  Graphite

  Silicon dioxide
• Simple molecular substance

  Consist of small molecules, such as Cl2, O2 and H2O

  O—O
• Bonding in a simple molecular substance

  Strong covalent bonds between atoms but weak intermolecular forces between the different molecules
• Why do simple molecular substances have low melting and boiling points

  Weak intermolecular forces therefore requiring a small amount of energy to break