This problem offers you two ways to test reactions - use them to investigate your ideas about speeds of reaction.
Investigate how avalanches occur and how they can be controlled
Build a mini eco-system, and collect and interpret data on how well the plants grow under different conditions.
How much energy has gone into warming the planet?
Simple models which help us to investigate how epidemics grow and die out.
Is it really greener to go on the bus, or to buy local?
Practise your skills of proportional reasoning with this interactive haemocytometer.