Question

(i) Which is largest in size Cu⁺ , Cu²⁺ or Cu and why?

(ii) Which element in periodic table has highest ionization energy (IE)?

(iii) Which element is more metallic Mg or Al and why?

Answer 1

(i) Among Cu⁺ , Cu²⁺ or Cu, Cu is largest in size due to less effective nuclear charge.

Cu 

No. of protons = 29,

No. of electrons = 29

Cu⁺ 

No. of protons = 29,

No. of electrons = 29-1 = 28

Cu²⁺

No. of protons = 29,

No. of electrons 29-2 = 27

(ii) In the periodic table, helium (He) has highest ionization energy (IE).

(iii) Among Mg or Al, Mg is more metallic due to its low ionization energy.