Question: For each alkane: (a) classify each carbon atom as 1°, 2°, 3°, or 4°;

(b) classify each hydrogen atom as 1°, 2°, or 3°.

Inorganic compounds, the carbon atoms are classified by the number of carbon atoms directly linked.

For example, a carbon attached directly to one other carbon atom is called a primary carbon atom and is represented as $1^0$carbon.

Similarly, carbon atoms attached to two other, three other, and four other carbon atoms are called secondary, tertiary, and quaternary carbon atoms and are represented as $2^0$, $3^0$, and $4^0$carbon atoms, respectively.

Classification of shaded carbon atoms

The hydrogen atoms are classified based on the carbon atom to which they are attached.

For example, a hydrogen atom attached to a $1^0$carbon is called a$1^0$ hydrogen, and so on.

Classification of shaded hydrogen atoms

All primary hydrogen atoms are written in pink color; the secondary hydrogen atoms are written in green color, and tertiary hydrogen atoms are written in blue color.

(a)

The carbon atoms are classified as:

Classification of all carbon atoms in A

Classification of all carbon atoms in B

(b)

The hydrogen atoms are classified as:

Classification of all hydrogen atoms in A

Classification of all hydrogen atoms in B