KS3/4 Demonstrating Chemistry: Exciting Elements 1

Some do’s and don’ts written by CLEAPSS (Consortium of Local Education Authorities for the Provision of Science Services)

NB. This is not an exhaustive list. If in doubt please contact CLEAPSS for more advice. Tel: 01895 251496, Fax: 01895 814372 or e-mail:

Tips : using alkali metals

  • Protect yourself and the students with safety screens
  • Pupils to be 2 to 3 metres away
  • Dab off oil with absorbent paper
  • Use small, clean cut, pieces of metal

Tips : rubidium and caesium

  • Special risk assessment required
  • Consult an organisation such as CLEAPSS

Tips : burning sodium in chlorine

  • Use a fume cupboard and wear goggles
  • When cool, carefully place the brick in a bowl of cold water to destroy any unreacted sodium

Tips : burning calcium in air

  • Wear heat-resistant gloves and goggles
  • Use several sheets of heat-resistant paper
  • Protect the bench

Tips : reduction of copper oxide using magnesium powder

  • Use a safety screen and wear goggles
  • Burn off the plastic in the bottle top prior to use
  • Stand well back until flash is complete
  • If it fails to flash, turn off the gas at the tap and wait for the mixture to cool

Tips: reacting iron and sulphur

  • Use less than 2 grams in a hard, glass test tube
  • For pupils, use less than 0.2g in small test tubes
  • Plug the test tube with mineral wool to reduce the risk of ignition

Tips : reacting sulphur with zinc

  • Use a safety screen and wear goggles
  • Burn off the plastic in the bottle top prior to use
  • Stand well back until flash is complete
  • If it fails to flash, turn off the gas at the tap and wait for the mixture to cool

Tips : fluorine

  • Do not attempt any reactions in schools with the element fluorine nor the compounds, hydrogen fluoride and hydrofluoric acid.

Tips : reaction between hydrogen and chlorine

  • A special risk assessment is required for the explosion of hydrogen and chlorine

Tips : reaction hydrogen with bromine

  • A special risk assessment is required for the burning of hydrogen/bromine mixtures

Tips : reactions of halogens with iron wool

  • Use a fume cupboard and wear eye protection
  • Wear gloves for handling liquid bromine
  • Consult CLEAPSS for further details