Mixtures

Physical combination of 2 or more pure substances. They are not chemically combined, just near each other.

The ratio of components can be varied   (Ex:  5% salt solution vs a 10% salt solution)

Each component retains its original properties

The components can be separated by physical means

Mixtures are either heterogeneous or homogeneous

hetero means "different"

Particles are not evenly distributed.

From the same mixture, one sample will look different from another sample.

Components can often be visually distinguished.

homo means "same"

Particles are evenly distributed.

Samples taken from the mixture are consistent with each other (uniform composition)

Components cannot be visually distinguished.

Also known as solutions

homogeneous mixtures

main component is called the solvent

dissolved component(s) are called solute

When water is the solvent, called an aqueous solution

(aq) is shorthand for aqueous

Salt water , NaCl _(aq)

sugar water , C₆H₁₂O_{6 (aq)}

air

metal alloys (brass, bronze)