Diffusion of colour in water | Johnstone’s triangle worksheets | 11–14 years

Develop learners’ thinking about diffusion at three different conceptual levels: macroscopic, sub-microscopic and symbolic.

This resource is made up of a Johnstone’s triangle worksheet which can be used to introduce the three different conceptual levels in the context of coloured substances diffusing in water. Demonstrate diffusion using a potassium manganate(VII) crystal and a visualiser or alternatively get learners to observe dyes from coloured sweets diffusing in a whole class practical.