Question

According to the quantum mechanics, correct statements concerning the electron in the hydrogen atom include which of the following?
I) It moves in a definite orbit around the nucleus.
II) It is associated with definite energy levels.
III) It occupies a fixed position in space with reference to the nucleus.
A) I only
B) II only
C) I and III only
D) II and III only
E) I, II, and III

Answer 1

As per the quantum mechanical theory, the electron is regarded to have both particles as well as wave character. The statements given are a part of Bohr’s postulates for hydrogen atoms.

Complete step by step solution:
The electron revolves around the nucleus in fixed energy levels called stationary states. These orbits are called “stationary states” because they are involved with a fixed amount of energy. These electrons are associated with amount of energies when in a particular orbital and as these electrons, accept or give away electrons, they take up or give away energy to either get excited to the orbital of higher energy or the jump down from an orbital of higher energy to an orbital of lower energy. The electron occupies a fixed space in reference to the nucleus as according to the wave mechanical model, the electron is thought to be “standing wave”. Hence all the statements in this regard are true.

So, the correct answer is option E.

Note:
According to the wave mechanical model of the electron, the electron is said to have the character of both particles and waves and the electron waves are treated in the same way as matter waves are treated.
This theory was initially presented by De-Broglie through his “Wave-particle” duality theory. The theory states that all matter waves have the quality of both particle and wave and the wavelength is related to the momentum of the particle by the following relation:
$\text{ }\lambda\text{ = }\dfrac{\text{h}}{\text{p}}$ Where h is planck's constant, $\text{ }\lambda\text{ }$ is the wavelength, and p is the momentum of the particle. This is a generalization of Einstein's equation.