Atoms may have different numbers of neutrons. Atoms are the smallest fraction of an element that can exist, and still show the properties of the element. They consists of electrons (negatively charged), protons (positively charged), and neutrons (no charge). The number of electrons is equivalent to the number of protons normally however an atom may loose or pick up electrons and have a positive charge or negative charge. The number of neutrons in the nucleus may vary within a given element to give varieties of atoms we call isotopes.
The stomach normally secretes acid that is essential in the digestive process and this helps in the breaking down of food during digestion. Acidity is responsible for ulcer, dyspepsia, heartburn and the formulation of the ulcer. One way to experiment on how the acid is neutralized is by using vinegar and starch.