# Question ad8fd

Mar 16, 2017

The bonds with the most covalent character are those in B. ${\text{SiCl}}_{4}$.

#### Explanation:

You look at the electronegativities of the atoms in the bonds and then calculate the electronegativity differences ΔEN.

Method 1. A quantitative method

Here are the electronegativities of the atoms.

$\boldsymbol{\textcolor{w h i t e}{m m m l} \text{Sr"color(white)(mm)"Sn"color(white)(mll)"Si"color(white)(mm)"Cl}}$
$E N \textcolor{w h i t e}{m l} 0.95 \textcolor{w h i t e}{m l} 1.90 \textcolor{w h i t e}{m l} 1.96 \textcolor{w h i t e}{m l} 3.16$

Now, we calculate the electronegativity differences for the $\text{M-Cl}$ bonds.

bb(color(white)(mmmmmmmmmll)ΔEN)#
$\text{Sr-Cl"color(white)(ml)"|0.95 - 3.16| = 2.21}$
$\text{Sn-Cl"color(white)(m)"|1.90 - 3.16| = 1.26}$
$\text{Si-Cl"color(white)(ml)"|1.96 - 3.16| = 1.20}$

$\text{Sn}$ is a metal. It has metallic bonds.

The bond that has the smallest electronegativity difference will have the greatest covalent character.

The $\text{Si-Cl}$ bond has the smallest difference, so it has the greatest covalent character.

Method 2. A qualitative method

$\text{Sn}$ is a metal. It has metallic bonds, not covalent bonds.

$\text{Sn}$ and $\text{Sr}$ are both metals. Their bonds with the nonmetal $\text{Cl}$ will have mostly ionic character.

$\text{Si}$ is a metalloid. It is closest to $\text{Cl}$ in the Periodic Table, so its bonds to $\text{Cl}$ should have the most covalent character.