Question

The potential energy curve for the$H_2$ molecule as a function of internuclear distance is:

• A.

  

• B.

  

• C.
• D.

  

Answer 1

The correct option is B

The explanation for the correct option:

1. As we know that when two $\mathrm{H}$-atoms come closer then due to the force of attraction between a nucleus of one $\mathrm{H}$-atom and the electron of another $\mathrm{H}$-atom, the potential energy initially decreases as potential energy converts into kinetic energy.
2. Then after reaching a certain value the force of repulsion between the nucleus of both $\mathrm{H}$-atoms or repulsion between the electrons of both $\mathrm{H}$-atoms comes into the picture and due to this, the potential energy increases steeply.
3. As for two $\mathrm{H}$-atoms initially force of attraction is dominating and at a shorter distance force of repulsion is stronger.
4. This can be clearly visible in option B.
5. 

Hence, the correct option is B.