The IUPAC name of the compound `CH_3 - underset(C_2 H_5) underset( । )CH -CH_3` is 2-ethylpropane.

Explanation

To determine the IUPAC name of the compound `CH3 - C(C2H5) - CH - CH3`, we will follow a systematic approach. Here are the steps:

### Step 1: Write the Compound in Expanded Form
The given compound can be expanded as follows:
- The `C2H5` group can be broken down into `CH2-CH3`.
- Therefore, the structure can be represented as:

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