Summary Make a milkshake by blowing bubbles in milk (plus flavourings) to make a foam. Science content Chemistry: States of Matter, Properties of Materials (K-7) Chemistry: Physical Changes, Solutions, Mixtures and Separating (2, 4, 5, 6) Lessons activity is in Bubbles Foam in foods Materials large cups (to contain the foam made) whole milk, about one cup is plenty optional: flavourings straw Procedure Make a foam drink, by adding air bubbles to milk. Give students a cup of milk and a straw (and a squirt of flavouring). Ask them to blow bubbles in their drink to make foam, then drink their "milkshake". The bubbles are air blown into the drink, which are stabilized by components in milk. Optional: do the foam molecule test on the component molecules of milkshake (protein, fat, sugar), to find out which ones make the foam. (The fat and protein.) The foam is a kind of mixture called a colloid. See the attachment for other kinds of colloids and mixtures. Attached documents mixtures_summary.pdf Grades taught Gr 1 Gr 2 Gr 3 Gr 4 Gr 5