(solved)Question 3.32 of NCERT Class XI Chemistry Chapter 3

$\displaystyle \underline{\underline{\text{Part (a) - Li and O}}}$

Li is $\displaystyle \text{[He]}2s^1$ G1 valence of 1

O is $\displaystyle \text{[He]}2s^22p^4$ G16 valence of 2

$\displaystyle Li_2O \text{ (ionic)}\:\underline{Ans}$

$\displaystyle \underline{\underline{\text{Part (b) - Mg and N}}}$

Mg is $\displaystyle \text{[Ne]}2s^2$ G1 valence of 2

N is $\displaystyle \text{[He]}2s^22p^3$ G15 valence of 3

$\displaystyle Mg_3N_2 \text{ (covalent)}\:\underline{Ans}$

$\displaystyle \underline{\underline{\text{Part (c) - Al and I}}}$

Aluminum has valency of 3, and iodine is a halogen of valency 1

$\displaystyle AlI_3 \text{ (covalent)}\:\underline{Ans}$

$\displaystyle \underline{\underline{\text{Part (d) - Si and O}}}$

Si valency 4, oxygen 2

$\displaystyle SiO_2 \text{ (covalent)}\:\underline{Ans}$

$\displaystyle \underline{\underline{\text{Part (e) - P and F}}}$

P valency 3, F has 1

$\displaystyle PF_3 \text{ (covalent)}\:\underline{Ans}$

$\displaystyle \underline{\underline{\text{Part (f) - 71 and F}}}$

Z = 71 config is $\displaystyle [Xe]6s^24f^{14}5d^{1}$ lutetium

hence, valence of Z = 71 is ($\displaystyle 6s^2$ + $\displaystyle 5d^1$) = 3

$\displaystyle LuF_3 \text{ (covalent)}\:\underline{Ans}$