Here's why:

* Combination Reaction: A reaction where two or more reactants combine to form a single product.

In this case:

* Reactants: Hydrogen (H₂) and Oxygen (O₂)

* Product: Hydrogen Peroxide (H₂O₂)

The equation represents the formation of hydrogen peroxide from its elemental components.

Important Note: This reaction doesn't happen spontaneously under normal conditions. You need a catalyst and specific conditions to make hydrogen peroxide from hydrogen and oxygen.