Question

how many lone pairs are there in the lewis structure of ammonia? a 4 b 2 c 3 d 1

Explanation:

Step1: Determine the Lewis structure of ammonia ($NH_3$)

Nitrogen ($N$) has 5 valence electrons. Hydrogen ($H$) has 1 valence electron. In $NH_3$, there are 3 $N - H$ bonds (each bond uses 2 electrons). The total number of electrons used in bonding is $3\times2 = 6$ electrons.

Step2: Calculate the remaining electrons for lone pairs

The total number of valence electrons in $NH_3$ is $5+(3\times1)=8$ electrons. After using 6 electrons in bonding, the number of remaining electrons is $8 - 6=2$ electrons. Since a lone pair consists of 2 electrons, the number of lone pairs is $\frac{2}{2}=1$.

Answer:

a 1