2-methylbut-2-ene will be represented as

Options

A. `CH_3 - underset(CH_3) underset(| ) (CH ) - CH_2 - CH_3`
B. `CH_3 - underset(CH_3) underset(| ) C =CH -CH_3`
C. `CH_3 - CH_2 - overset(CH_3)overset(|)(C ) - CH_2`
D. `CH_3 - underset(CH_3) underset(|) (CH ) - CH = CH_2`

Explanation

To represent 2-methylbut-2-ene, we will follow these steps:

### Step 1: Identify the Parent Chain
The name "but-2-ene" indicates that the parent chain has four carbon atoms (butane).

**Hint:** The prefix "but-" indicates a four-carbon chain.

### Step 2: Draw the Carbon Skeleton
We will draw a linear chain of four carbon atoms.

**Hint:** Draw four carbon atoms in a straight line.

### Step 3: Number the Carbon Atoms
Number the carbon atoms in the chain starting from one end. For example, we can number them from left to right as 1, 2, 3, and 4.

**Hint:** Numbering helps to identify the position of substituents and double bonds.

### Step 4: Add the Double Bond
The name "but-2-ene" indicates that there is a double bond between the second and third carbon atoms. We will place a double bond between C2 and C3.

**Hint:** The "ene" suffix indicates the presence of a double bond.

### Step 5: Add the Methyl Group
The "2-methyl" part of the name indicates that there is a methyl group (-CH₃) attached to the second carbon atom. We will add a methyl group to C2.

**Hint:** A methyl group consists of one carbon atom and three hydrogen atoms.

### Step 6: Complete the Valences with Hydrogen Atoms
Finally, we will complete the valences of the carbon atoms with hydrogen atoms. Each carbon can form four bonds, so we will add hydrogen atoms accordingly.

**Hint:** Each carbon atom should have four bonds total (including bonds with other carbons and hydrogen).

### Final Structure
The final structural formula for 2-methylbut-2-ene will look like this:

```
CH3
|
CH3-C=C-CH3
```

This structure represents 2-methylbut-2-ene correctly.

### Summary
The structural representation of 2-methylbut-2-ene is a four-carbon chain with a double bond between the second and third carbon atoms and a methyl group attached to the second carbon.