To determine the correct statements about bond order, we need to understand the concept of bond order and how it is calculated. The bond order can be calculated using the formula:
\[ \text{Bond Order} = \frac{1}{2} \times (\text{Number of electrons in bonding orbitals} - \text{Number of electrons in antibonding orbitals}) \]
Now, let's analyze each statement one by one.
### Step 1: Analyze Each Statement
1. **Statement 1: Bond order can have a negative quantity.**
- **Analysis:** Bond order represents the number of bonds between two atoms. A negative bond order would imply that there are more antibonding electrons than bonding electrons, which means that there is no stable bond formed. Thus, this statement is **incorrect**.
2. **Statement 2: Bond order has always an integral value.**
- **Analysis:** Bond order is calculated as half the difference between the number of bonding and antibonding electrons. If the difference is an odd number, the bond order could be a fraction (e.g., 1.5). Therefore, this statement is also **incorrect**.
3. **Statement 3: Bond order can assume any positive, integral, or fractional value including zero.**
- **Analysis:** Bond order can indeed be positive, integral, fractional, or even zero. For example, in the case of beryllium (Be), the bond order is calculated as zero, indicating no bond. This statement is **correct**.
4. **Statement 4: Bond order is a non-zero quantity.**
- **Analysis:** As established in the analysis of statement 3, bond order can be zero. Therefore, this statement is **incorrect**.
### Conclusion
Based on the analysis:
- **Correct Statement:** Statement 3 is correct.
- **Incorrect Statements:** Statements 1, 2, and 4 are incorrect.
### Final Answer
The correct statement about bond order is that it can assume any positive, integral, or fractional value including zero.
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