Practise your skills of proportional reasoning with this interactive haemocytometer.
Explore the distribution of molecular masses for various hydrocarbons
Investigate the molecular masses in this sequence of molecules and deduce which molecule has been analysed in the mass spectrometer.
What is the chance I will have a son who looks like me?
Simple models which help us to investigate how epidemics grow and die out.
A problem about genetics and the transmission of disease.