Answer:
OH^-
Explanation:
Any substance that is able to neutralize acidity in the stomach is generally known as an antacid. There are various kinds of antacids that are in common use. It should be noted that the stomach is usually slightly acidic.
Milk of magnesia is the substance magnesium hydroxide with chemical formula Mg(OH)2. A solution of milk of magnesia contains Mg^2+ and OH^-.
Hence the negative ion contained in milk of magnesia is the hydroxide ion OH^-.
A gas can move around freely while a solid is hard and can’t move around freely
