Sodium metal can be used for drying diethyl ether and benzene and not ethanol.

Explanation

To understand why sodium metal can be used for drying diethyl ether and benzene but not ethanol, we need to analyze the chemical properties of these compounds and the behavior of sodium metal.

### Step-by-Step Solution:

1. **Understanding Sodium Metal**: Sodium (Na) is a highly reactive metal with a strong affinity for water. It can attract and react with water molecules, which is why it is used to dry organic solvents.

**Hint**: Remember that sodium's high reactivity is due to its tendency to lose its outermost electron easily.

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