1. Chemical Formula:

* Ammonia: NH₃ (one nitrogen atom and three hydrogen atoms)

* Methane: CH₄ (one carbon atom and four hydrogen atoms)

2. Structure:

* Ammonia: Has a pyramidal shape with the nitrogen atom at the apex.

* Methane: Has a tetrahedral shape with the carbon atom at the center.

3. Bonding:

* Ammonia: Nitrogen forms three covalent bonds with hydrogen, and there is a lone pair of electrons on the nitrogen atom.

* Methane: Carbon forms four covalent bonds with hydrogen.

4. Properties:

* Ammonia: Has a pungent, choking odor and is a colorless gas at room temperature. It is highly soluble in water and forms an alkaline solution.

* Methane: Is a colorless, odorless gas at room temperature. It is sparingly soluble in water and is not a base.