Chapter 2 Properties of Matter

Remember…• Matter is anything that has

mass and takes up space• Can you name something that

is not matter?• What is the absence of matter

called?– Vacuum

Extensive vs. Intensive

• Properties used to describe matter can be classified as extensive or intensive

• Extensive property – dependant on the amount of matter in a sample

• Intensive property – independent of the amount of matter in a sample

Examples• Extensive:

– Mass, volume, length

• Intensive: – Density, hardness, color

Substances• Substance - Matter that has a uniform

and definite composition

• Every sample of a given substance has identical properties because every sample has the same composition

• Examples of substances include copper, gold, mercury, water, and carbon dioxide.

Physical Properties• Can be observed or measured without

changing the substance’s composition

• Can you think of any physical properties? – Hardness, color, conductivity, malleability,

melting point, boiling point, physical state

– Definite shape– Definite volume– Not easily

compressed

• Plasma and Bose - Einstein condensates are 2 states of matter that are not as common

 Shape Volume Compressibility

Solid definite shape definite volume not easily compressed

Liquid

Gas

• Physical Change – some properties of the material change, but the composition of the material stays the same

• May be reversible or irreversible

Physical Changes

Physical Changes

• Boil, freeze, melt, condense• Break, split, grind, cut, crush

• If the composition of the material changes, it is NOT a physical change.

Mixtures

• A mixture is a blend of 2 or more physical components

• Mixtures can be classified as heterogeneous or homogeneous

Mixtures

• Heterogeneous – composition is NOT uniform

• Homogeneous – uniform composition• Homogeneous mixtures are sometimes

called solutions • A phase can be used to describe any part of

a sample with uniform composition (example: 2 phases - oil and water)

Classifying Mixtures

• Food coloring• Ice cubes in liquid water• Mouthwash• Mashed, unpeeled potatoes• Olive oil• Salt water• Gasoline• Chocolate chip ice cream

Separating Mixtures

• Physical properties can be used to separate mixtures• Example: Assume you are asked to separate a mixture of

olive oil and vinegar. • You could decant (pour off) olive oil from vinegar. What

physical property allows you to do this? • You could cool the mixture until the oil solidifies, but the

vinegar is still a liquid. What physical property allows you to do this?

Distillation

• A liquid is boiled to produce a vapor that is then condensed into a liquid.

put in pic of dist set up

Elements and Compounds

• An element is the simplest form of matter• A compound two or more elements that are

chemically combined in a fixed proportion• Compounds can only be broken down by

chemical means (not physical)

Elements and Compounds

• Compounds usually have properties that are quite different from those of their component elements.

• Can you think of any examples?• NaCl, H2O, C6H12O6

Matter Map

Chemical Changes

• The composition of the matter always changes

• Examples include: burning, rotting, rusting, decomposing, fermenting, exploding, and corroding

Chemical Reactions

• There are four clues that provide evidence of a chemical change:– Transfer of energy– Change in color– Production of a gas– Formation of a precipitate

Chemical Reactions

• Be careful, the clues are only indicators that a chemical change may have occurred.

• What is the only way to tell for sure that a chemical reaction has taken place?

Law of Conservation of Mass

• During any chemical reaction, the mass of the products is equal to the mass of the reactants

• In any physical change or chemical reaction, matter can neither be created or destroyed.

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