Geometrical isomers differ in:

Options

A. Position of functional group
B. Position of atoms
C. Spatial arrangement of atoms
D. Length of carbon chain

Answer

To solve the question regarding geometrical isomers, we need to understand what geometrical isomerism is and how it manifests in molecules.

### Step-by-Step Solution:

1. **Understanding Geometrical Isomerism**:
- Geometrical isomers are compounds that have the same molecular formula and connectivity of atoms but differ in the spatial arrangement of atoms or groups around a double bond or a ring structure.

2. **Identifying the Types of Geometrical Isomers**:
- There are primarily two types of geometrical isomers: **cis** and **trans**.
- **Cis Isomer**: The similar or bulky groups are on the same side of the double bond.
- **Trans Isomer**: The similar or bulky groups are on opposite sides of the double bond.

3. **Example of Geometrical Isomerism**:
- Consider **but-2-ene** (C4H8) as an example:
- The structure can be represented as:
- **C=C** with two CH3 (methyl) groups and two H (hydrogen) atoms attached to the carbon atoms.
- In the **cis form**, both CH3 groups are on the same side of the double bond.
- In the **trans form**, the CH3 groups are on opposite sides of the double bond.

4. **Conclusion**:
- The key difference between geometrical isomers lies in the **spatial arrangement of atoms** in three-dimensional space around the double bond. This spatial arrangement leads to different physical and chemical properties.

5. **Final Answer**:
- Geometrical isomers differ in the **spatial arrangement of atoms in space**.