Which one of the compounds shown below, is not an isomer of the others ?

Options

A.
B.
C.
D.

Explanation

To solve the question of which compound is not an isomer of the others, we will follow these steps:

### Step 1: Identify the Compounds
Let's label the compounds as A, B, C, and D based on the options provided in the question.

### Step 2: Determine the Molecular Formula
We need to find the molecular formula for each compound. An isomer must have the same molecular formula but different structural formulas.

#### For Compound A:
- Count the number of carbon (C) atoms: 8
- Count the number of hydrogen (H) atoms: 14
- Molecular formula: C8H14

#### For Compound B:
- Count the number of carbon (C) atoms: 8
- Count the number of hydrogen (H) atoms: 14
- Molecular formula: C8H14

#### For Compound C:
- Count the number of carbon (C) atoms: 8
- Count the number of hydrogen (H) atoms: 14
- Molecular formula: C8H14

#### For Compound D:
- Count the number of carbon (C) atoms: 8
- Count the number of hydrogen (H) atoms: 12
- Molecular formula: C8H12

### Step 3: Compare the Molecular Formulas
Now, we compare the molecular formulas:
- Compounds A, B, and C have the molecular formula C8H14.
- Compound D has a different molecular formula, C8H12.

### Step 4: Conclusion
Since compounds A, B, and C have the same molecular formula and can be considered isomers of each other, while compound D has a different molecular formula, it is clear that compound D is not an isomer of the others.

### Final Answer
The compound that is not an isomer of the others is **Compound D**.

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