Using both sets of jars, match the items that sound alike. Try this experiment to help students understand the composition of limestone and marble. Hard boil an egg, and place it in a jar filled with vinegar. Loosely cover the jar and place it where students can observe it. Bubbles should be forming around the shell.
Some bubbles leave the egg, and some remain attached to the egg, enabling it to float.
One day later remove the egg and rinse in water. The shell should have disappeared, leaving a leathery membrane covering the egg. The egg can be bounced like a ball. Next, drop a piece of chalk into the vinegar. Bubbles will rise and pieces of the chalk will disappear.