Question

What does bond order refer to?
A) How many bonds are there between two atoms.
B) Where the atoms are on the periodic table.
C) How many electrons each atom shares
D) How many electrons each atom shares or absorbs.
E) How many bonds each atom makes.

Answer 1

Hint: The answer to this question can be obtained on the basis of the molecular orbital theory which gives the definition for the bond order and also about calculation of bond order and the number obtained from the formula gives the answer.

Complete Solution :
Earlier in the inorganic chemistry chapters, we have studied various theories of the bonds and the structure of atoms like VSEPR theory, MOT, VBT etc.
Now, let us see what is meant by bond order by considering one simple instance.
Let us take dinitrogen as an instance.
Now we have the formula to calculate the number of bonds present as,
$B.O.=\dfrac{1}{2}\left( {{N}_{B}}-{{N}_{A}} \right)$
where, B.O. = Bond order of a given molecule
${{N}_{B}}$= number of electrons in bonding molecular orbital
${{N}_{A}}$= number of electrons in anti bonding molecular orbital.

Based on molecular orbital theory, for dinitrogen we have:
$B.O.=\dfrac{1}{2}(10-4) = 3$
Thus, the bond order for dinitrogen is three.
This implies that there are three bonds between two nitrogen atoms.
Therefore based on this fact, the correct answer is option A) How many bonds are there between two atoms.
So, the correct answer is “Option A”.

Additional Information:
Molecular orbital theory mainly gives the information about the bond order, bond length and also bond energy. This theory makes use of constructing a molecular orbital diagram and assigning the electrons present in each level.

Note: Here, the main thing to be observed is that the bond order is just the name which gives the total number of bonds between two atoms and not to be confused with option C) even if two bonds are made by the sharing of electrons between two atoms.