Name the rule that is observed during the addition of an unsymmetrical molecule to an unsymmetrical alkene.

Explanation

To answer the question, we need to identify the rule that governs the addition of an unsymmetrical molecule to an unsymmetrical alkene. The rule is known as **Markovnikov's Rule**.

### Step-by-Step Solution:

1. **Understanding the Components**:
- An unsymmetrical alkene is a hydrocarbon that has a double bond and does not have identical groups attached to both carbons of the double bond.
- An unsymmetrical molecule, such as a protic acid (e.g., HBr, HCl, HI), can add across the double bond of the alkene.

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