xplain why sea water is a mixture whereas purified water is not.

Definition: A mixture is a substance made by combining two or more different materials in such a way that no chemical reaction occurs. A pure substance is a form of matter that has a constant composition and properties that are constant throughout the sample.

Sea Water: Sea water is a mixture because it contains many different substances dissolved in it. These substances include salts (like sodium chloride), gases (like oxygen and carbon dioxide), organic material, and even living organisms. Each of these substances retains its own chemical identity within the sea water, which is why it is considered a mixture.

Purified Water: Purified water, on the other hand, is not a mixture because it has been treated to remove all impurities and contaminants. The process of purification removes all substances other than the water molecules themselves. Therefore, purified water is a pure substance, not a mixture.

Conclusion: So, sea water is a mixture because it contains many different substances that retain their own chemical identities. Purified water is not a mixture because it contains only one type of molecule - water molecules.