Homemade Lava Lamps
These are really simple but effective and fun. We used two glasses from the cupboard, food colouring, water, oil and Alka Seltzer tablets which are easy to pick up in a supermarket.
As you probably know oil and water don’t mix. We poured water into each glass, about 3/4 full, and then added a few drops of food colouring. We then poured in some olive oil that we had in the kitchen. You can decide how much to use but you should see a layer of oil on top of the water in the glass.
Finally, you add the Alka Seltzer tablet. We broke up the tablet into little pieces before putting it in to speed up the reaction. The tablet starts to dissolve and react in the water. The oil begins to separate into little globules and it moves around the glass making the lava lamp effect!