Atomic and Molecular Structure

How to Calculate Bond Order?

Introduction to Bond Order

The bond order is something that pairs two atoms with their atoms. Furthermore, finding the bond of an atom is not difficult if you know the electron and shell of electrons.

Bond order is an atomic level phenomenon, in which the elements share their electrons to fill their valance shell. Also, it can bond two or more substance together in a compound.

Bond Order

Calculating Bond Order Method- 1 (to find bond order quickly, 1/2 bond order)

Antibonding Electrons- According to the molecular orbital theory, Bond order is half of the difference between bonding and anti-bonding electrons.

Bond order = Number of the electrons in bonding molecule – Number of the electrons in the anti-bonding molecule(antibonding electrons)/ 2

Furthermore, the higher the bond order the more stable the molecule will become. In addition, the more the electron that enters the orbital the more stable the molecule will become. Besides, each electron that enters the anti-bonding molecule will destabilize the new molecule.

Suppose in the shell of a hydrogen atom can hold 2 electrons but there is only 1 electron. Also, when 2 hydrogen atom come together they share their electrons to complete each other’s y shell.

In this way, two orbital forms and no orbital forced to move to higher orbital. Thus the binding order of the hydrogen atom is
Bond order = Number of the electrons in bonding molecule – Number of the electrons in anti-bonding molecule / 2

Bond Order = 2-0 / 2 = 1

This form the common molecule H2 or hydrogen gas.

Calculating Bond Order Method 2 (Visualizing of bond structure)

The most basic form of a covalent bond is the order of one. Furthermore, a double covalent is the order of two, and a triple covalent bond is the order of three and this goes on and on. Besides, the bond order is the number of the bonded electron that holds a pair of two atoms together.

Moreover, the electrons move in orbital around the nucleus of the atom and each orbital can hold up to 2 electrons. Most noteworthy, depending on the complexity and size of the atom and can have up to four orbitals.

Also, when the first orbital fills up then the atoms move to next orbital until the shell is full. For understanding this draws a diagram and take an example like; use – for a single bond, = for a double bond, and ≡ for a triple bond.

Also, use the elements Hydrogen (H) and Chlorine (Cl). Now mark the number covalent shell in the molecules.

Hydrogen has 1 valance electron and Chlorine also has 1 valance electron. So, both the molecule will share their one electron forming the bond like this H – Cl. And this sharing will form HCl (Hydrochloric acid).

Calculating Bond Order Method 3 (Calculating bond order for orbital theory)

Draw a diagram of electron orbital shell of the element and draw each orbital further from the centre (nucleus). Furthermore, according to entropy property, the electrons will seek to populate the lowest orbital shell available.

Besides, know the difference between anti-bonding and bonding orbitals. When the two atoms come together to form a molecule, they try to seek each other electrons to fill the lowest possible state of their electron orbital shell.

Furthermore, the bonding electron is the electrons that stick together and fall in the lowest state. While anti-bonding electron is unbounded or free electrons that move to the higher orbital state.

Solved Question for You

Question. How many electrons are there in the outer shell of Sulphur?

A. 6
B. 4
C. 5
D. 3

Answer. The correct answer is option A.

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