question_answer 1)

  If the electronic configuration of an element is \[1{{s}^{2}}\text{ }2{{s}^{2}}\text{ }2{{p}^{6}}\text{ }3{{s}^{2}}\text{ }3{{p}^{6}}\text{ }3{{d}^{2}}\text{ }4{{s}^{2}}\], the four electrons involved inchemical bond formation will be : (a)\[3{{p}^{6}}\]                                               (b) \[3{{p}^{6}},4{{s}^{2}}\]                         (c)\[3{{p}^{6}},3{{d}^{2}}\]                                (d) \[3{{d}^{2}},4{{s}^{2}}\]

Answer:

  (d) It is a d-block or transition metal. Its maximum valency depends on the total number of ns and (n - 1)d electrons if less than 6 electrons are present on (n-1)d orbitals.