A pure solution is a homogeneous mixture where the components are uniformly distributed throughout the mixture and cannot be separated by simple physical means. Here are some examples:

Gases:

* Air: A mixture of nitrogen, oxygen, carbon dioxide, and other gases.

* Helium: A pure element, not a mixture.

* Natural Gas: Mostly methane with some other hydrocarbons.

Liquids:

* Seawater: A mixture of water, salts, and dissolved minerals.

* Vinegar: A solution of acetic acid in water.

* Sugar water: A solution of sugar dissolved in water.

Solids:

* Brass: An alloy of copper and zinc.

* Bronze: An alloy of copper and tin.

* Steel: An alloy of iron and carbon.

Note: The concept of "pure" can be relative. For example, "pure" water is still a mixture of hydrogen and oxygen, but it is considered pure in the context of a chemical compound. Similarly, a "pure" solution of sugar in water might contain trace impurities, but for most purposes, it's considered a pure solution.

It's also important to note that solutions are not limited to these categories. They can be found in all states of matter, and there are many more examples of pure solutions beyond these listed.