Chapter 37, Problem 1FTD

To determine

The phenomenon of repulsive interaction between atoms when two atoms together to form a molecules.

Answer to Problem 1FTD

The repulsive interaction between the atoms is due to exclusion principle when the outer shells of atoms are completely filled. The exclusion principle forces the electrons to goes into higher energy states which increase the overall energy and resulting in a repulsive interaction.

Explanation of Solution

The formation of molecules by interaction of two atoms involves both electric forces and quantum mechanical effects associated with exclusion principle.

The Exclusion principle states that two electron in an atom or molecules cannot have the same electronic quantum number. As an orbital contain a maximum of only two electrons, the two electrons must have opposing spins. When atoms are squeezed closely together, interactions involving the spins of their outermost electrons also result in attractive or repulsive interactions.

When the outer shells of atoms are completely filled, the exclusion principle forces electrons from separate atoms into different states as the atoms are brought together. One or more electron goes into higher energy states, increasing the overall energy and resulting in a repulsive interaction. Finally, if atoms get very close, the electrical repulsion of the nuclei becomes important.

Conclusion:

Thus, the repulsive interaction between the atoms is due to exclusion principle when the outer shells of atoms are completely filled. The exclusion principle forces the electrons to goes into higher energy states which increase the overall energy and resulting in a repulsive interaction.