Question

The element Cu undergoes chemical reaction to form an ion with oxidation number +2. sub questions (a) write the subshell electronic configuration (b) Can this element show variable valency? why? (c) write the chemical formula of one compound formed when this element reacts with Cl​

Answer 1

Answer:

Cu - 1s2 2s2 2p6 3s2 3p6 3d10 4s1

a) Cu donates 2 electron from the last shell

Cu 2+ - 1s2 2s2 2p6 3s2 3p6 3d9

b) yes it can show variable valency because,there is only a small difference of energy between the outermost s subshell and the penultimate d subshell of transition elements so these elements show variable valency.

c) Cl atomic no - 17 ( 2, 8 , 7 )

valency = -1

Cu = +2 (already given in the question)

Cu  2      Cl 1=

Cu1  Cl 2=

CuCl2