Classifying Matter

Classifying a substance by physical properties (state, boiling point, color, density…) is not specific enough –one substance can exist in more than one phase example: ice (solid), water (liquid), and steam (gas) are all made of H 2 O which is called dihydrogen monoxide –many substances have the same density, color… –different substances can all exist in the same phase salt, gold, sand, and ice are all solids It is often better to classify substances by what they are made out of and their chemical properties

Matter MixturePure Substance YESNO YESNO Homogeneous Mixture Heterogeneous Mixture NO ElementCompound YESNO SolutionColloid Are the particles one kind of atom? Are all the particles alike? Are the particles well-mixed and mixed evenly? Is one substance dissolved in another? YES

Pure Element, Compound, or Mixture?

Heterogeneous Mixture –does not look the same throughout –not mixed very well –can often see different particles mixed together –often can be easily separate –examples: salad dressing, rocks, concrete Mixtures

Homogeneous Mixture –looks the same throughout –mixed very well –often can’t see different particles mixed together –often difficult to separate –examples: steel, milk, salt water, Kool Aid®

–Most common kind is a solution  always has a substance that is dissolved in another substance the substance that is dissolved is called the solute the substance that does the dissolving is the solvent  examples: salt water, alloys (solids dissolved in solids)  a substance that dissolves in another substance is soluble; if it can’t, it is insoluble

Solutions Quiz!