Yes, H₂O (water) can be decomposed by a chemical change.

Here's how:

* Electrolysis: This is the most common method. By passing an electric current through water, the water molecules are split into their component elements: hydrogen gas (H₂) and oxygen gas (O₂).

The chemical equation for this reaction is:

2H₂O(l) → 2H₂(g) + O₂(g)

Here's a breakdown:

* Decomposition: The process of breaking down a compound into simpler substances.

* Chemical Change: A change where new substances are formed with different properties.

* Electrolysis: Using electricity to break down a substance.

Let me know if you'd like more details about electrolysis!