Mixture Matter Homogeneous MatterHeterogeneous Matter Element Compound Mixture SolutionColloid Suspension Pure Substance

Elements, Mixtures and Compounds Element Mixture Compound

Homogeneous Matter  Matter that has identical properties throughout  Examples:

Heterogeneous matter  matter that has parts with different properties

Elements  Use chemical symbol  Cannot be changed into a simpler substance by heating or by any chemical process  can exist as either atoms (e.g. argon) or molecules (e.g., nitrogen). Microscopic view of the molecules of the element nitrogen (gas phase). Microscopic view of the atoms of the element argon (gas phase).

Compounds  Made of more than one element  Two or more atoms chemically combined  Can only be separated chemically  Examples: water, sugar, salt, carbon dioxide  Properties of the compound are often very different than the properties of the individual elements (example: NaCl)  Made up of molecules (two or more atoms chemically bonded together)

Compounds, cont. Molecule is the smallest particle of a compound that has all the properties of the compound Chemical formula representing a compound Examples: NaCl, C 6 H 12 O 6, CO 2 Microscopic view of the molecules of the compound water (gas phase). Oxygen atoms are red and hydrogen atoms are white.

Mixtures  Matter that consists of two or more substances physically mixed together but not chemically combined  Substances keep their separate identities & most of their own properties  Substance may change in physical appearance  Because substances retain their original properties they may be separated out by simple physical means (no chemical reactions involved).  Homogeneous (particles are small, not easily recognized and do not settle when allowed to stand)  Heterogeneous (does not appear to be the same throughout) throughout)

Solutions  Mixture formed when one substance dissolves in another  All components are in the same phase  Solvent – does the dissolving  Solute – gets dissolved  Saturated solution – solvent cannot hold any more solute  Examples

Concentration  Amount of solute dissolved per amount of solution

Solubility  Measure of how much of a solute can be dissolved in a given amount of solvent under certain conditions  Solubility curve

Colloid  different components are in different phases, such as solids in liquids or liquids in gases, but the mixing is so thorough that the different phases cannot be distinguished  milk – homogeneous mixture of proteins and fats finely dispersed in water  blood – composed of finely dispersed blood cells in water  particles are large enough to scatter light to scatter light

Dispersing medium Dispersed phase Example GasLiquidFog GasSolidSmoke LiquidGas Whipped Cream LiquidLiquid Milk, mayo LiquidSolid Paint, ink, blood, ice cream SolidGasMarshmallow SolidLiquid Butter, gelatin, cheese, jelly SolidSolid Opal, Pearl, styrofoam

Suspension  Heterogeneous fluid that contains solid particles that are sufficiently large and settle over time  Examples: dirt in water; orange juice