Elements that are in the same column of the periodic table are called a chemical group . In the following experiments we will test the properties of elements belonging to one of the chemical groups – the alkali metals . Activity A Demonstration Experiment The properties of the group of alkali metals Purpose : to learn about the properties of the alkali metals sodium and potassium . Protective gear : safety goggles , fume closet . Equipment : safety goggles , a jar containing lumps of sodium immersed in kerosene , a 250 ml beaker containing 150 ml of water , tweezers , knife . Activity : A . Find the elements sodium and potassium in the periodic table . Where are they located ? B . The sodium is in a jar , covered with kerosene . Look at it and describe its appearance .  אל הספר
מטח : המרכז לטכנולוגיה חינוכית