Pure primary amines `underline("can be prepared ")`by the action of ammonia on alkyl halides.

Explanation

To prepare pure primary amines by the action of ammonia on alkyl halides, we can follow these steps:

### Step 1: Understanding the Reaction
The reaction involves ammonia (NH₃) acting as a nucleophile that attacks an alkyl halide (R-X, where R is an alkyl group and X is a halogen). This is a nucleophilic substitution reaction.

**Hint:** Recall that nucleophiles are species that donate an electron pair to form a chemical bond.

### Step 2: Reaction Mechanism
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