If you have ever heated a marshmallow over a fire you will know that the inside starts to melt. Why do you think this is? Come up with a scientific explanation; remember to think about heat, solids and liquids.
Follow the link to a marshmallow experiment you can try at home:
http://www.planet-science.com/categories/under-11s/our-world/2011/12/giant-marshmallows!.aspx Write up your experiment. Top Tip: you can find some free KS2 experiment