Q. 6.102 - An Introduction to General, Organic, and Biological Chemistry

Question

State the number of valence electrons, bonding pairs, and lone pairs in each of the following Lewis structures: 

Step-by-Step Solution

Answer

a. $8$ valence electrons, $2$ bonding pairs, and $2$ lone pairs of electron.

b. $8$ valence electrons, $3$ bonding pairs, and $1$ lone pair of electron.

c. $20$ valence electrons, $2$ bonding pairs, and $8$ lone pairs of electron.

Part(a) Step 1: Given information

We have been given the Lewis structure of ${\mathrm{H}}_2\mathrm{O}$ molecule.

We need to find the number of valence electrons, bonding pairs, and lone pairs 

Part(a) Step 2: Explanation

Each Hydrogen atom has $1$ valence electron and Oxygen has $6$ valence electrons so the given Lewis structure of ${\mathrm{H}}_2\mathrm{O}$ molecule have $8$ valence electrons. It has $2$ bonding pairs and $2$lone pairs of electron oven Oxygen atom.

Part(b) Step 1: Given information

We have been given the Lewis structure of ${\mathrm{NH}}_3$ molecule.

We need to find the number of valence electrons, bonding pairs, and lone pairs.

Part(b) Step 2: Explanation

Each Hydrogen atom has $1$ valence electron and Nitrogen has  $5$ valence electrons so the given Lewis structure of ${\mathrm{NH}}_3$  molecule have $8$  valence electrons. It have $3$  bonding pairs and  $1$ lone pair of electron oven Nitrogen atom.

Part(c) Step 1: Given information

We have been given the Lewis structure of ${\mathrm{Br}}_2\mathrm{O}$ molecule.

We need to find the number of valence electrons, bonding pairs, and lone pairs.

Part(c) Step 2: Explanation

Each $\mathrm{Br}$ atom have $7$ valence electrons and Oxygen have $6$ valence electrons so the given Lewis structure of ${\mathrm{Br}}_2\mathrm{O}$ molecule have $20$  valence electrons. It has $2$ bonding pairs and $8$ lone pairs of electron.