Question

The number of valence electrons in $C{H}_{3}C{H}_{2}Cl$ is:

• A. 14
• B. 12
• C. 18
• D. 20

Answer 1

The correct option is D 20

Atomic number of carbon = 6
Electronic configuration of Carbon is $\left[He\right]2s^{2}2p^2$
Number of valence electrons = 4

Similarly the number of valence electrons in hydrogen $\left(H\right)$ and chlorine $\left(Cl\right)$ are 1 and 7 respectively.

In $C{H}_{3}C{H}_{2}Cl$, we have 2 carbon atoms, 5 hydrogen atoms and a chlorine atom.

Hence, the total number of valence electrons in $C{H}_{3}C{H}_{2}Cl=(4\times 2)+(1\times 5)+7=20$