Stewart used a packet of Revels to get over the point of some particles being fundamental (the pure chocolate revel) and other particles being non-fundamental (e.g. the orange centred revel)
Other activities with sweets included a model containing three small sweets wrapped in aluminium foil. This represented the three quarks in a neutron and proton. The students were given a task where they had to predict the charge on the two different types of quark for a neutron and a proton.