This resource has been designed to be a simple and fun diagnostic assessment to carry out at the start of a science unit on reversible and irreversible changes.   Your students will need approximately 20 small, colourful candy-covered chocolates or lollies arranged in a circle on the edge of a plate. As they pour warm water in the centre, they will marvel as the colours run.   This worksheet supports your students to record their observations and attempt to explain what they think happened. There are two worksheets to a page so you can print the number of copies that you need and then cut them in half down the middle.   The activity demonstrates a reversible physical change. The candy sugar coatings dissolved into the water but did not change as a substance.   This resource is part of our Chemical Sciences Year 6 UNIT PLAN.