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: science@cleapss.org.uk
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