1. A substance that does *not* contain water molecules:
* Dry substances: Many things are naturally dry, like sand, rocks, metals, and plastics. These substances don't have water molecules as a part of their composition.
* Dehydrated substances: You can remove water from some things, like fruit or vegetables, through drying processes. They're still the same substance, just without the water.
2. A substance that is *not* dissolved in water:
* Oils and fats: These are hydrophobic, meaning they don't mix with water and form separate layers.
* Gases: Most gases aren't soluble in water, like oxygen and nitrogen.
3. A substance that *doesn't require* water to exist:
* Everything in space: Outer space is a vacuum, so there's no water present. Stars, planets, asteroids, etc., all exist without water.
To give you a more specific answer, I need more context. What kind of substance are you thinking about?
