Chapter 2, Problem 1E

Why is the quantum-mechanical model of the atom important for understanding chemistry?

Interpretation Introduction

To determine:

The reason for the importance of quantum mechanical model of atom for understanding chemistry.

Answer to Problem 1E

Solution:

This model explains the presence of electron in an atom and its effect on chemical and physical properties and helpful in explanation of modern periodic table.

Explanation of Solution

Quantum mechanical model of atom is important in chemistry because of the following reasons:

1. It can explain the electronic structure of larger atoms than hydrogen which are too complex to be explained by the classical atom model.
2. It introduces the concept of uncertainty which says that the momentum and position both cannot be determined exactly simultaneously. If momentum is accurately determined, position of the particle has a large uncertainty.
3. The equation is: $\Delta x\Delta p\ge h/4\pi$ . Here $\Delta x$ is uncertainty in position and $\Delta p$is uncertainty in momentum.
4. Quantum mechanical theory can explain the hyperfine splitting in spectra of atoms.
5. Quantum mechanical theory of atoms introduced concepts of principal quantum number, angular momentum quantum number, magnetic quantum number and spin quantum number. These quantum numbers are necessary to correctly describe the electronic configuration of atoms.
6. It could explain Zeeman effect, but the classical theory of atoms could not explain it.

Conclusion

This model explains the presence of electron in an atom and its effect on chemical and physical properties and helpful in explanation of modern periodic table.