Pure Substances & Mixtures

A pure substance is a material that has a constant composition and consistent properties throughout. Examples include elements like gold and compounds like water.

A mixture is a combination of two or more substances where each retains its own properties. Mixtures can be homogeneous or heterogeneous.

A homogeneous mixture is a mixture that has a uniform composition throughout. An example is saltwater.

A heterogeneous mixture is a mixture where the components are not uniformly distributed. An example is a salad.

A pure substance has a uniform appearance and cannot be separated into other substances by physical means.

A pure substance has a fixed composition and distinct properties, while a mixture consists of two or more substances that can be separated and do not have a fixed composition.

Evaporation is the process by which a liquid turns into vapor, often used to separate a liquid from a dissolved solid.

Straining with a sieve is a method used to separate larger particles from smaller ones in a mixture, often used in cooking.

Chemical separation involves changing the chemical composition of a substance to separate its components, which is not applicable for identifying pure substances.

A substance that is uniform in appearance looks the same throughout and does not have visible differences in its composition.