Unit - Periodic classification of elements Evaluate yourself . Atomic number : IUPAC temporary symbol : Unbinilium IUPAC temporary symbol : Ubn Possible electronic configuration :[Og] 8s . Electronic Configuration : (n – )d ns for n = , the electronic configuration is, 1s 2s 2p 3s 3p 4s 3d 4p 4d 5s Atomic number : th group th period (d block element) = Zirconium . Electronic Configuration of Aluminium Al s s p s p ( ) n ( ) Group no.
of electrons Contribution of each electron to 'S' value Contribution of a particular group (n – ) (n – ) . . . .
. . ∴ Effective nuclear charge = Z – S = – . (Z eff ) Al = .
Electronic Configuration of chlorine s s p s p Group no. of electrons Contribution of each electron to 'S' value Contribution of a particular group . . (n – ) .
. (n – ) S = . ∴ Effective nuclear charge = Z – S = – . (Z eff ) cl = .
(Z eff ) cl > (Z eff ) Al and. Hence r cl < r Al . . X + , Y + , Z – are isoelectronic.
∴ Effective nuclear charge is in the order ( ) ( ) ( ) Z Z Z eff Z eff Y eff X < < and Hence, ionic radii should be in the order r r r Z Y X > > ∴ The correct values are, Species Ionic radii Z – Y + X + . Noble gases : Ioniation energy ranging from KJmol – to kJ mol – . For element X, the IE , value is in the n- n- 11th Std Chemistry 11th Std Chemistry - - - - range of noble gas, moreover for this element