Little chemists observe the effects of acid on calcium carbonate as an example of chemical change. As a demonstration you will place a raw egg in vinegar overnight, and as a lab activity, learners drip vinegar onto a piece of chalk. Cross curricular activities are suggested to go along with this investigation. Make sure not to use "dustless" chalk, but rather use the old-fashioned, non-coated chalk, or else the vinegar will be prevented from reacting with the calcium carbonate.