Draw the Lewis structures for butanol, ethanamide, and propanamine.

Butanol is an alcohol with four carbon atoms. We'll draw 1-butanol (n-butanol) as a straight chain.
Each carbon atom forms 4 bonds, and each hydrogen forms 1 bond. The oxygen atom forms 2 bonds and has 2 lone pairs to complete its octet.

Lewis Structure for Butanol:
H H H H | | | | H-C---C---C---C---O-H | | | | .. H H H H

Ethanamide is an amide with two carbon atoms. It contains a carbonyl group (C=O) and an amino group (-NH₂).
The first carbon forms 3 bonds with hydrogen and 1 bond with the second carbon. The second carbon forms a double bond with oxygen, a single bond with nitrogen, and a single bond with the first carbon. Oxygen forms 2 bonds (a double bond here) and has 2 lone pairs. Nitrogen forms 3 bonds (2 with hydrogen, 1 with carbon) and has 1 lone pair.

Lewis Structure for Ethanamide:
H O | || H-C---C---N-H | | .. H H

Propanamine is an amine with three carbon atoms. We'll draw 1-propanamine as a straight chain.
Each carbon atom forms 4 bonds, and each hydrogen forms 1 bond. The nitrogen atom forms 3 bonds (2 with hydrogen, 1 with carbon) and has 1 lone pair to complete its octet.

Lewis Structure for Propanamine:
H H H | | | H-C---C---C---N-H | | | | .. H H H H

Ethane is an alkane with two carbon atoms, meaning all bonds are single bonds.
Each carbon atom forms 4 bonds, and each hydrogen forms 1 bond. There are no lone pairs on carbon or hydrogen atoms in ethane.

Lewis Structure for Ethane:
H H | | H-C---C-H | | H H