Question

Which of the following statement is correct?

• A. Shape of orbital is determined by magnetic quantum number
• B. In hydrogen atom, degeneracy of $n^{th}$ state is $n^2$
• C. $3d_{z^2}$ has a nodal plane
• D. According to Hunds Rule, electrons are filled in degenerate orbitals of subshell in such a way so as to give maximum number of unpaired electrons with opposite spin

Answer 1

Answer: (B)

In hydrogen atom, degeneracy of $n^{th}$ state is $n^2$

Answer 2

The shape of an atomic orbital is determined by the azimuthal quantum number ($l$). The magnetic quantum number ($m_l$) determines the orientation of the orbital in space. In a hydrogen atom, the degeneracy of the $n^{th}$ state is $n^2$ because all orbitals with the same principal quantum number ($n$) have the same energy. The $3d_{z^2}$ orbital has two conical surfaces of nodes, not a nodal plane. Hund's rule states that electrons fill degenerate orbitals with parallel spins to maximize multiplicity, not opposite spins.