Golden rain

The precipitation of lead iodide from a solution of potassium iodide and lead nitrate is so dramatic and engaging that I use it both with my 11–14 and 16–18 year old students. The younger students see this reaction when I’m introducing ionic bonding. I show the reaction again to my older students and ask them to sketch particle diagrams to explain what they are seeing.

The ‘seen it before’ mentality is easily avoided with this reaction – the ‘golden rain’ demonstration is a stunning suspension of glistening yellow crystals.

Declan Fleming provides a step by step guide, with a supporting video, to preparing and teaching the 'golden rain' demonstration. Teaching tips and goals suggest ways to avoid or clear up any misconceptions and to support using this demonstration to teach ionic bonding.