Which one of the following statements is wrong?

Which one of the following statements is wrong?
  1. de-Broglie's wavelength is given by λ=hmv , were m=mass of the particle,v=group velocity of the particle.
  2. The uncertainty principle is ΔE×Δt≥h4π.
  3. Half-filled and fully-filled orbitals have greater stability due to the greater exchange energy, greater symmetry and more balanced arrangement.
  4. The energy of 2s orbital is less than the energy of 2p orbital in case of hydrogen-like atoms.

Solution

(i) λ=hp=hmv
(ii) Δx.Δp=h4π
Δx×Δp×dtΔt≥h4π     ∴ΔpΔt=f
fΔx    Δt≥h4π, fΔx=ΔE
ΔE.Δt≥h4π
(iii) 3rd statement is true.
(iv) The energy of 2s-orbital and 2p-orbital in case of hydrogen like atoms is equal because they are single electron species.

Asked in: NEET 2017

Practice more Structure of Atom questions on Aicharya