Exams › JEE Main › Chemistry

Which of the following sets of quantum numbers is not allowed?

1. n = 3, ℓ = 2, m = 0, s = + 1/2
2. n = 3, ℓ = 2, m = −2, s = + 1/2
3. n = 3, ℓ = 3, m = −3, s = − 1/2
4. n = 3, ℓ = 0, m = 0, s = − 1/2

Correct answer: n = 3, ℓ = 3, m = −3, s = − 1/2

Solution

For a given n, the azimuthal quantum number l ranges 0 to n-1. With n=3, l can be 0,1,2 only, so n=3, l=3, m=-3 is not allowed.

Related JEE Main Chemistry questions

• At what wavenumber does the first line of the hydrogen Balmer series occur in the atomic spectrum?
• In the hydrogen emission spectrum, a spectral series has its limit at 12186.3 cm⁻¹. This series is identified as
• Two rapidly moving particles X and Y have de Broglie wavelengths of 1 nm and 4 nm, respectively. If the mass of X is nine times the mass of Y, what is the ratio of their kinetic energies, X: Y?
• Given that Planck’s constant is 6.63 × 10⁻³⁴ J s and the speed of light is 3.0 × 10⁸ m s⁻¹, which of the following is nearest to the wavelength, in nanometres, of light having frequency 8 × 10¹⁵ s⁻¹?
• A lithium ion and a proton are each accelerated through the same potential difference. If their de Broglie wavelengths are λ₁ and λ₂, respectively, and m_(Li) = 9mₚ, what is the ratio λ₁: λ₂?
• The ionisation energy of He⁺ is 19.6 × 10⁻¹⁸ J atom⁻¹. What is the energy of the first stationary state (n = 1) of Li²⁺?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →