Final answer:
Saliva breaking down a piece of bread and an antacid tablet reacting with water both involve chemical reactions that result in the formation of new compounds. Enzymatic hydrolysis by saliva breaks down carbohydrates, while antacids neutralize stomach acid through a neutralization reaction.
Step-by-step explanation:
Saliva breaking down a piece of bread and an antacid tablet reacting with water share the common process of chemical reactions involving acids and bases. Saliva contains the enzyme amylase, which catalyzes the breakdown of carbohydrates in bread into sugars. This is a type of hydrolysis reaction, as water in the saliva helps break down the starch into simpler sugars. Similarly, an antacid tablet contains compounds like Mg(OH)2 or NaHCO3 which react with the excess acid in the stomach to form water, a salt, and relieve acidity through a neutralization reaction. Both processes involve the transformation of substances into new compounds via chemical means and often generate salts as a result of the interactions between acids and bases.