Heartburn is when stomach acid is produced in abnormal amounts or location. One of the symptoms of heartburn is a burning feeling in the chest or abdomen. They can be recognized by their sour taste and their ability to react with other substances. Acids are confirmed as an acid by their pH. The pH of acids range from 0-6.9. An antacid is any substance that can neutralize an acid.
All antacids are bases.
A base is any substance that can neutralize an acid. The pH of a base is 7.1-14. All antacids have chemical in them called a buffer. When an antacid is mixed with an acid the buffer tries to even out the acidity and that is how stomach acid gets neutralized. Almost all foods and drinks and even medicines have ingredients that are different acids.