When water (H₂O) is chemically decomposed, it breaks down into its constituent atoms:

* Hydrogen (H)

* Oxygen (O)

The chemical equation for this decomposition is:

2H₂O → 2H₂ + O₂

This means that two molecules of water (2H₂O) produce two molecules of hydrogen gas (2H₂) and one molecule of oxygen gas (O₂).