1.2. For example: (a) Calculate effective nuclear charge in Nitrogen for 2p electron.

o Electronic configuration- (1s2) (2s2, 2p3).o Screening constant, σ = (0.35 × 4) + (0.85 × 2) = 3.10o Effective nuclear charge, Z* = Z – σ = 7 – 3.10 = 3.90

3. 3

(b) Calculate effective nuclear charge and screening constant seen in 3p electron in Silicon.

o Electronic configuration- (1s2) (2s2, 2p6)(3s2, 3p2).o σ = (0.35 × 3) + (0.85 × 8) + (1 × 2) = 9.85o Z* = Z – σ = 14 – 9.85 = 4.15

4. 4

(c) Calculate effective nuclear charge in Zinc for 4s electron & for 3d electron.

o Electronic configuration- (1s2) (2s2, 2p6)(3s2, 3p6)(3d10)(4s2).o For 4s electron,o σ = (0.35 × 1) + (0.85 × 18) + (1 × 10) = 25.65o Z* = Z – σ = 30 – 25.65 = 4.35o For 3d electron,o σ = (0.35 × 9) + (1 × 18) = 21.15o Z* = Z – σ = 30 – 21.15 = 8.85

5. 5(d) Calculate effective nuclear charge on one of 6s electron in tungsten. (At. No. =74)

o Electronic configuration- (1s2) (2s2, 2p6)(3s2, 3p6)(4s2, 4p6) (3d10) (4f14) (5s2, 5p6)(5d4), (6s2)o σ = (0.35 × 1) + (0.85 × 12) + (1 × 60) = 70.55o Z* = Z – σ = 74 – 70.55 =3.45