On Saturday, youngsters and their parents gathered at McDonnell Hall to learn about the science of chocolate, courtesy of professors Howard Stone, chair of the Department of Mechanical and Aerospace Engineering, and Bonnie Bassler, chair of the Department of Molecular Biology.

The students received insight into the answers to such questions as where chocolate comes from, what makes a chocolate bar smooth and creamy, and what are hydrophobic (water repelling) and‚Äã amphiphilic (in parts water repelling and attracting) materials. This was the 9th annual event. (Photos below by Sameer Khan/Fotobuddy)