What are the reactive sites for addition reactions in unsaturated hydrocarbons? Give one example.

Explanation

### Step-by-Step Solution:

1. **Understanding Unsaturated Hydrocarbons**:
- Unsaturated hydrocarbons are organic compounds that contain carbon and hydrogen atoms, characterized by the presence of at least one double bond (alkenes) or triple bond (alkynes) between carbon atoms.

2. **Identifying Reactive Sites**:
- The reactive sites for addition reactions in unsaturated hydrocarbons are the carbon atoms involved in the double or triple bonds.
- Specifically, the carbon atoms in a double bond are referred to as "olefin carbons," while those in a triple bond are called "reactive carbons."
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