a. The valence electrons of carbon, hydrogen, and nitrogen are four, one, and five, respectively. The electrons are represented as bonds between the atoms, and the lone pair that is present in nitrogen is also indicated in the Lewis structures.

Representation of Lewis structure of a
b. The valence electrons of carbon, hydrogen, nitrogen, and oxygen are four, one, five, and six, respectively. Bonds are utilized to indicate the electrons between the atoms. The oxygen consists of a lone pair, and this is also indicated in the Lewis structure.

Representation of Lewis structure of b
c.The valence electrons of carbon, hydrogen, and nitrogen, and oxygen are four, one, five, and six, respectively. The total count of valence electrons is identified.

Representation of Lewis structure of c
d. The valence electrons of carbon, hydrogen, and nitrogen are four, one, and five, respectively. The valence electrons of each atom are added to obtain the total number.

Representation of Lewis structure of d