Correct the following statements by changing the underlined part of the sentence.
Natural rubber is `ul("a condensation polymer.")`

Explanation

To correct the statement "Natural rubber is a condensation polymer," we need to identify the correct type of polymerization that occurs in the formation of natural rubber.

1. **Identify the Monomer**: The monomeric unit of natural rubber is isoprene, which has the chemical structure CH2=C(CH3)-CH=CH2.

2. **Understand the Polymerization Process**: Natural rubber is formed through a process called addition polymerization. In this process, the double bonds in the isoprene monomers open up and link together to form long chains without the elimination of any small molecules (like water).

3. **Correct the Statement**: Since natural rubber is not formed by condensation polymerization (which involves the elimination of small molecules), we replace "a condensation polymer" with "an addition polymer."

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