The source of energy for chemosynthesis is inorganic chemical compounds. Unlike photosynthesis, which uses sunlight, chemosynthesis harnesses energy from the oxidation of inorganic molecules.

Here are some examples of inorganic compounds used in chemosynthesis:

* Hydrogen sulfide (H2S): This is commonly used by bacteria found in hydrothermal vents and cold seeps.

* Methane (CH4): This is used by methanotrophic bacteria.

* Ammonia (NH3): This is used by nitrifying bacteria.

* Iron (Fe2+): This is used by iron-oxidizing bacteria.

These organisms use the energy released from breaking down these inorganic compounds to create organic molecules like carbohydrates, which are the building blocks of life.

Therefore, chemosynthesis is an important process for life in environments where sunlight is not available, such as deep-sea vents, caves, and even some soils.