Question

What is the bond order of \( \text{Be}_2 \) molecule?

• A. Two
• B. Three
• C. Zero
• D. One

Hint:

For molecules with an even number of electrons in antibonding and bonding orbitals, the bond order may be zero, as seen in \( \text{Be}_2 \).

Answer 1

The Correct Option is C

Step 1: Understanding bond order.
Bond order is calculated as the difference between the number of bonding electrons and antibonding electrons, divided by 2. In the case of \( \text{Be}_2 \), the molecule has a bond order of 0 because the antibonding electrons cancel out the bonding electrons.
Step 2: Analyzing the options.
(A) Two: Incorrect. \( \text{Be}_2 \) does not have a bond order of two.
(B) Three: Incorrect. \( \text{Be}_2 \) has a bond order of zero, not three.
(C) Zero: Correct — The bond order of \( \text{Be}_2 \) is zero, indicating no bond formation.
(D) One: Incorrect. Bond order of one is found in molecules like \( \text{H}_2 \), but not in \( \text{Be}_2 \).
Step 3: Conclusion.
The correct answer is (C) Zero, as the bond order of \( \text{Be}_2 \) is zero.