Final answer:
The correct answer is 4) NaBr which is sodium bromide. Antacids contain active ingredients that neutralize excess stomach acid. Sodium bromide is not an active ingredient in antacids.
Step-by-step explanation:
The correct answer is 4) NaBr which is sodium bromide.
Antacids are substances used to neutralize excess stomach acid. Common active ingredients in antacids include sodium bicarbonate (NaHCO₃), magnesium hydroxide (Mg(OH)₂), and calcium carbonate (CaCO₃).
Sodium bromide (NaBr) is not an active ingredient in antacids and does not have the ability to neutralize stomach acid. It is instead used in other applications such as in photography and as a sedative.