Every once in a while the Chemistry Institute of the University of Amsterdam opens its doors to the families of the chemistry students. Parents, siblings, grandparents and other family members can learn a little bit about chemistry by attending a lecture and doing some experiments in the lab. This picture was taken by my mother while my father was busy with an experiment that involved the addition of vinegar to baking powder, creating a lot of carbon dioxide, which could be observed as bubbles. My grandmother and aunt are in the back. What I love about this picture is how the curiosity and concentration can be read from the faces of my family.