Which of the following does not apply to bonding in metals ?

Options

A. Non - directional bonds
B. Mobility of valence electrons
C. Delocalisation of electrons
D. Highly directed bonds

Answer

To solve the question "Which of the following does not apply to bonding in metals?", we will analyze the properties of metallic bonding and identify which statement is incorrect.

### Step-by-Step Solution:

1. **Understanding Metallic Bonding**:
- Metallic bonding is characterized by a 'sea of electrons' where electrons are not bound to any specific atom and can move freely. This results in properties such as electrical conductivity and malleability.

2. **Identifying Key Properties**:
- **Non-directional Bonds**: Metallic bonds are generally non-directional. This means that the force of attraction between the positive metal ions and the delocalized electrons does not have a specific direction.
- **Mobility of Valence Electrons**: In metals, the valence electrons are free to move, which contributes to conductivity.
- **Delocalization of Electrons**: The electrons in metallic bonds are delocalized, meaning they are spread out over many atoms rather than being associated with a single atom.

3. **Analyzing the Options**:
- We need to determine which of the given options does not apply to metallic bonding.
- The options likely include statements about the properties of metallic bonds.

4. **Conclusion**:
- Since metallic bonds are non-directional, have mobile valence electrons, and involve delocalization of electrons, the statement that does not apply to metallic bonding is the one that suggests metallic bonds are highly directed.

Thus, the answer is that the property of "highly directed bonds" does not apply to bonding in metals.

### Final Answer:
The option that does not apply to bonding in metals is **"highly directed bond"**.