Question

the element with atomic number 29 undergoes chemical reaction to form and I want with oxidation number + 2

a) write down the sub shell electronic configuration of this ion

b) can this elements show variable valency why ​

Answer 1

The element with atomic number 29 is Copper.

Explanation:

Copper is the element with symbol Cu and atomic number 29.

• The electron configuration of copper(II) is 1s2 2s2 2p6 3s2 3p6 3d9. The copper atom loses its 4s2 electrons to form the +2 ion.
• Copper is one of the transition elements and it exhibits variable oxidation states.
• It has variable valencies: +1 and +2.
• The ion with valency +1 is called Cuprous and and the ion with valency +2 is called Cupric.
• They are denoted as Cu(I) and Cu(II) respectively.

Answer 2

The answer to the following questions are:

(a) The element with atomic number 29 is Copper (Cu).

- Its ground state electronic configuration is:

Cu (29) = 1s², 2s², 2p⁶,3s², 3p⁶, 4s¹, 3d¹⁰

- In +2 oxidation state, the ion is Cu²⁺.

- Its electronic configuration is:

Cu²⁺ = 1s², 2s², 2p⁶, 3s², 3p⁶, 3d⁹

(b) Yes, this element, i.e., Copper can show variable valency.

- Copper is a transition element and hence it exhibits variable valency.

- Cu can show two valencies namely +1 and +2.

- Cu can only show two valencies because it has too much d electrons and hence fewer orbitals for the sharing of electrons.