Question

Which of the following species contains three bond pairs and one lone pair around the central atom?

• A. $N{H}_2^{-}$
• B. $PC{l}_3$
• C. $H_{2}O$
• D. $B{F}_3$

Answer 1

The correct option is B $PC{l}_3$

Representation of Lewis structure:
1. Pair of bonded electrons is represented by means of a dash usually called a bond.
2. Lone pairs or non-bonded electrons are represented by dots.
3. Electron represent in the last shell of atoms are called valence electrons.

$\left(a\right)$ Structure of $N{H}_2^{-}$
Number of bond pairs: $2$
Number of lone pairs: $2$
$\left(b\right)$ Structure of $PC{l}_3$Number of bond pairs: $3$
Number of lone pair: $1$

$\left(c\right)$ Structure of $H_{2}O$

Number of bond pairs: $2$
Number of lone pair: $2$

$\left(d\right)$ Structure of $B{F}_3$

Number of bond pairs: $3$
Number of lone pair: $0$