91Ó°ÊÓ

The carbon atoms are classified into $1^0$,$2^0$, $3^0$and $4^0$carbons.

• The $1^0$carbon is only attached to one carbon.
• The $2^0$carbon is attached to the two carbon atoms.
• The $3^0$carbon is attached to the three carbon atoms.
• The $4^0$carbon is attached to the four carbon atoms.

The hydrogen atoms are classified into $1^0$, $2^0$and $3^0$hydrogen.

• The $1^0$hydrogen is only attached to the $1^0$carbon.
• The $2^0$hydrogen is attached to the $2^0$carbon.
• The $3^0$hydrogen is attached to the $3^0$carbon.

a. The $1^0$,$2^0$, $3^0$and $4^0$carbon is shown in the images as follows:

Classification of carbon atoms in [1]

Classification of carbon atoms in [2]

Classification of carbon atoms in [3]

Classification of carbon atoms in [4]

b.The classification of hydrogen is shown as follows:

Classification of hydrogen atoms in [1]

Classification of hydrogen atoms in [2]

Classification of hydrogen atoms in [3]

Classification of hydrogen atoms in [4]