Give two reasons for supporting that water is a compound and not a mixture.

Water is a compound, not a mixture, because its elements are chemically combined in a fixed ratio and it has unique properties different from hydrogen and oxygen.

Reason 1: Fixed Composition

Water always has two hydrogen atoms and one oxygen atom (H₂O). This fixed ratio proves it is a compound. In mixtures, components can be present in any proportion.

Reason 2: New Properties

Water has properties very different from hydrogen and oxygen. For example:

• Hydrogen is a flammable gas.
• Oxygen supports combustion.
• But water (H₂O) is a liquid that puts out fire.

This shows water is not just a mixture but a new substance formed by chemical bonding.

Other Supporting Points

• Water cannot be separated into hydrogen and oxygen by physical methods like filtration or evaporation. It requires electrolysis, a chemical method.
• Mixtures show properties of their components, while compounds show completely new properties.