1. Fill 1 cup with ice. Add room-temperature water until the cup is about 3/4 filled.
2. Add room-temperature water to another cup until it
is about 3/4 filled.
3. Wipe the outside of both cups with a paper towel to
be sure they are dry.
4. Allow the cups to sit for about 1–3 minutes. Look at
the outside of each cup. Use your finger to test for
any liquid on the outside of the cups.
Matter on the move (continued)