− Second excited state E eV E eV ∴ = − = − . Electronic configuration of Fe + is 1s 2s 2p 3s 3p 4s 3d Five unpaired electrons. ↿ ↿ ↿ ↿ ↿ 3d Electronic configuration of Mn + is 1s 2s 2p 3s 3p 4s 3d ∴ Five unpaired electrons. Electronic configuration of Ar: 1s 2s 2p 3s 3p no unpaired electrons.
. 4f no. of electrons f-orbital Principal energy level 11th Std Chemistry 11th Std Chemistry - - - - n = ; f orbital l = ⇒ m l = – , – , – , , + , + , + Out of two electrons, one electron occupies 4f orbital with m l = – and another electron occupies 4f orbital with m l = – . ∴ All the four quantum numbers for the two electrons are Electron l m l m s 1e – – + / 2e – – + / .
Electronic configuration of Fe + : 1s 2s 2p 3s 3p 4s 3d Electronic configuration of Ni + : 1s 2s 2p 3s 3p 4s 3d Fe + has stable 3d half filled configuration. EVALUATION I Choose the best answer: . (c) . (c) .
x - J . (b) λ = 2λ . (d) Stark effect . (b) .
(d) n= to n= . (a) . (c) d z2 , d x2-y2 . (b) Spin quantum number .
(b) [Xe]4f 6s ; [Xe]4f 5d 6s ; [Xe]4f 6s . (c) 4l+ . (d) √ h/ π . (c) .
(c) . (a) . (a) ns→(n- )f→(n- )d→np . (b) (ii),(iv) & (v) .