Explain the formation of the hydrogen molecule according to the Valence Bond Theory.

The potential energy $\left(y\right)$ curve for ${\mathrm{H}}_2$ formation as a function of internuclear distance $\left(x\right)$ of the $\mathrm{H}$ atoms is shown below.

The bond energy of ${\mathrm{H}}_2$ is :

Give a brief account of Valence Bond Theory.

Given below are two statements : One is labelled as Assertion $\mathrm{A}$ and the other is labelled as Reason $\mathrm{R}$

Assertion $\mathrm{A}$ : Zero orbital overlap is an out of phase overlap.

Reason $\mathrm{R}$ : It results due to different orientation/ direction of approach of orbitals.

In the light of the above statements. Choose the correct answer from the options given below

Number of sigma bonds in ${\mathrm{P}}_4{\mathrm{O}}_{10}$ is:

What is true about $\mathrm{CO}$ molecule?

$\mathrm{a}.$ It has two lone pairs.

$\mathrm{b}.$ It has one dative bond.

$\mathrm{c}.$ It has two $\mathrm{\pi }$ bonds.

$\mathrm{d}.$ It has one $\mathrm{\sigma }$ bond.

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$

Overlapping leads to the formation of $\sigma$bonding molecular orbital in: