The number of subshells associated with n = 4 and m = –2 quantum numbers is

The oxidation states of transition metal atoms in K₂Cr₂O₇, KMnO₄ and K₂FeO₄, respectively, are x, y and z. The sum of x, y and z is _______.

The molecular geometry of SF₆ is octahedral. What is the geometry of SF₄ (including lone pair(s) of electrons, if any)?

Simplified absorption spectra of three complexes ((i), (ii) and (iii)) of Mn⁺ ion are provided below; their $$\lambda $$_max values are marked as A, B and C respectively. The correct match between the complexes and their $$\lambda $$_max values is
(i) [M(NCS)₆]^{(–6 + n)}
(ii) [MF₆]^{(–6 + n)}
(iii) [M(NH₃)₆]ⁿ⁺