If the antacid neutralizes stomach acid, it must be...

basic/alkaline

If the antacid neutralizes stomach acid, it must be a base.

If the antacid neutralizes stomach acid, it must be a base. Antacids are typically alkaline substances that can raise the pH of stomach acid. The most common active ingredients found in antacids are compounds such as calcium carbonate, magnesium hydroxide, and aluminum hydroxide, all of which have basic properties. These substances react with the excess stomach acid to form water and a salt, effectively reducing the acidity and providing relief from symptoms of acid reflux or heartburn. To determine if an antacid is a base, you can check its active ingredients or refer to its chemical formula or composition.