Write the name and chemical formula of bases present in milk of magnesia.

Milk of magnesia is a common name for a suspension of magnesium hydroxide in water. The key base present in milk of magnesia is **magnesium hydroxide**.

### Chemical Formula:
- **Name**: Magnesium Hydroxide
- **Chemical Formula**: \( \text{Mg(OH)}_2 \)

### Explanation:
- **Magnesium Hydroxide** is a white, powdery compound that is only slightly soluble in water. When mixed with water, it forms a suspension that is used as an antacid and a laxative.
- In the formula \( \text{Mg(OH)}_2 \):
- \( \text{Mg} \) represents magnesium, which has a valency of +2.
- \( \text{OH}^- \) represents the hydroxide ion, which has a valency of -1.
- Therefore, two hydroxide ions are required to balance the +2 charge from one magnesium ion.

Milk of magnesia is widely used for its neutralizing properties against stomach acid, making it effective for treating heartburn and indigestion.