Which of the following is the best evidence
that digestion involves chemical change?
a time is required to accomplish results.
b the products’ mass equals the reactants’
mass.
c different compounds are involved.
d new substances are produced.

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.