1. Stomach Acid: Your stomach produces hydrochloric acid (HCl), which is a strong acid, to help digest food.

2. Antacid Ingredients: Antacid tablets contain basic compounds like:

* Calcium carbonate (CaCO3): Found in Tums and Rolaids.

* Magnesium hydroxide (Mg(OH)2): Found in Milk of Magnesia.

* Sodium bicarbonate (NaHCO3): Found in baking soda.

* Aluminum hydroxide (Al(OH)3): Found in some antacids.

3. Neutralization Reaction: When these basic compounds come into contact with stomach acid, they react chemically to neutralize the acid. This reaction produces salt, water, and carbon dioxide gas.

Here's a simplified example:

* Calcium carbonate (CaCO3) + Hydrochloric acid (HCl) → Calcium chloride (CaCl2) + Water (H2O) + Carbon dioxide (CO2)

4. Relief from Heartburn: This neutralization process reduces the acidity of the stomach contents, providing relief from heartburn and indigestion.

Important Notes:

* Antacids provide temporary relief and do not address the underlying cause of heartburn.

* Long-term use of antacids can have side effects, so it's important to use them as directed and consult your doctor if you have frequent heartburn.

* Some antacids can interact with other medications, so it's essential to talk to your doctor or pharmacist if you're taking any other medications.