Bond energy of a molecule :

Options

A. Is always negative
B. Is always positive
C. Either positive or negative
D. Depends upon the physical state of the system

Answer

### Step-by-Step Solution:

1. **Understanding Bond Energy**:
- Bond energy is defined as the amount of energy required to break a bond between two atoms in a molecule.

2. **Nature of Bond Energy**:
- When a bond is broken, energy must be supplied to overcome the attractive forces between the atoms. This means that energy is absorbed from the surroundings.

3. **Sign of Bond Energy**:
- Since energy must be supplied to break a bond, the bond energy is always a positive quantity. This indicates that energy is required for the process.

4. **Conclusion**:
- Therefore, the bond energy of a molecule is always positive. This means that the correct answer to the question is that bond energy is always positive.

5. **Elimination of Options**:
- Based on the explanation, we can conclude that:
- Option A (always negative) is incorrect.
- Option B (always positive) is correct.
- Option C (either positive or negative) is incorrect.
- Option D (depends upon the physical state of the system) is also incorrect.

### Final Answer:
The bond energy of a molecule is always positive.

---