Whether the given compounds can show geometrical isomerism :
Pent-1-ene

Answer

To determine whether pent-1-ene can show geometrical isomerism, we need to analyze its structure and the conditions required for geometrical isomerism to occur.

### Step-by-Step Solution:

1. **Identify the Structure of Pent-1-ene**:
- Pent-1-ene is an alkene with the formula C₅H₁₀. It has a double bond between the first and second carbon atoms.
- The structure can be represented as follows:
```
CH2=CH-CH2-CH2-CH3
```

2. **Understanding Geometrical Isomerism**:
- Geometrical isomerism (also known as cis-trans isomerism) occurs due to restricted rotation around a double bond.
- For a compound to exhibit geometrical isomerism, each carbon atom involved in the double bond must have two different groups attached to it.

3. **Analyze the Double Bond in Pent-1-ene**:
- In pent-1-ene, the double bond is between the first carbon (C1) and the second carbon (C2).
- At C1, the groups attached are:
- One hydrogen (H)
- One alkyl chain (C2H5 or CH2-CH2-CH3)
- At C2, the groups attached are:
- One hydrogen (H)
- One alkyl chain (C3H7 or CH2-CH2-CH2-CH3)

4. **Check for Different Groups**:
- For geometrical isomerism to occur, both C1 and C2 must have different substituents.
- At C1, we have H and an alkyl group.
- At C2, we have H and another alkyl group.
- Since both C1 and C2 have the same type of substituents (hydrogen on both sides), there are no different groups to create cis and trans forms.

5. **Conclusion**:
- Since both carbon atoms involved in the double bond do not have two different groups attached, pent-1-ene cannot exhibit geometrical isomerism.

### Final Answer:
**Pent-1-ene cannot show geometrical isomerism.**