Quantum Mechanics | MCQs

Explanation

The velocity of a photon is independent of its wavelength. 

The velocity of a photon is determined by the speed of light in a vacuum, which is a constant value (approximately 299,792,458 meters per second) and does not change based on the photon's wavelength or amplitude.

The speed of light is a fundamental constant of nature. 

Explanation

A metastable state is an excited state of an atom or molecule that has a significantly longer lifetime compared to other excited states, but is still shorter than the ground state.

This means that an electron in a metastable state can stay in that state for a relatively long time before transitioning back to a lower energy level. 

Explanation

The Paschen series involves electron transitions ending at the third energy level (n=3) in a hydrogen atom.

These transitions emit photons in the infrared region of the electromagnetic spectrum.

Explanation

The photoelectric effect does not occur if the frequency of the incident light is below the threshold frequency.

The threshold frequency is the minimum frequency required for the incident photons to have enough energy to eject electrons from the surface of the material.

If the frequency is below this value, no electrons are emitted, regardless of the light intensity.

Explanation

The magnetic moment (μ) is related to the number of unpaired electrons (n) by the formula:

μ = √(n(n+2)) BM

Given μ = 5.92 BM, we can solve for n:

5.92 = √(n(n+2))

n(n+2) ≈ 35.25

n ≈ 5

Explanation

Explanation

Explanation

• De Broglie extended the wave-particle duality to electrons in 1923.
• He proposed that particles such as electrons exhibit wave-like properties.
• A hypothesis that was later confirmed experimentally and became a fundamental concept in quantum mechanics.

Explanation

Quantum numbers describe values of conserved quantities in the dynamics of a quantum system

Explanation

The radius of an atomic orbital increases with the square of the principal quantum number (n).
So, larger values of n result in electrons being farther from the nucleus:

Radius∝n2