Properties of Matter

Chapter 2

hydr ogen

element s

wat er

compounds

pur e subs t ances

salt wat er

homogenous

conc r et e

het er ogeneous

mix t ur es

M A T T E R

Pure Substances

• ELEMENTS• Cannot be broken

down into simpler substances.

• Can be found as solids, liquids, or gases

• Represented by symbols

• COMPOUNDS• 2 more elements

chemically joined together

• Can be broken down through chemical means

• Represented by a formula

Mixtures

•Homogenous• Appear the same

throughout.• Well-mixed• Examples:

• Heterogeneous• Can see different parts• Not very well mixed• Examples:

• The best mixed mixture.

• One substance is dissolved in another.

• Cannot be separated by filtering

• Particles are too small to be seen

A heterogeneous mixture that will separate over time

The particles in a suspension are larger than the particles dissolved in a solution

Cloudy appearance

Examples:

muddy water, oil & vinegar salad dressing

• Intermediate sized particles. Smaller than suspension but larger than solution.

• Particles are permanently suspended

• Will scatter light

Physical Properties

• A characteristic of matter that can be directly observed without changing the identity of the substance

Viscosity• The resistance of flow

in a liquid• How “thick” or “thin”

a liquid is• Examples of substance

that have high viscosity:

Conductivity

• The ability to conduct heat or an electric current

• High conductivity: metals

• Low conductivity: wood, rubber

Malleability vs ductility

• MALLEABLE• Ability to be

hammered into a thin sheet.

• Example:

• DUCTILE• Ability to be drawn

into a thin wire.• Example:

Melting and Boiling Points

• Very useful in determining unknown substances.

Density

• The amount of mass per unit volume

• D = M/V

Separating Mixtures

• Filtration = using a strainer or filter to separate on the basis of size of the particles.

Distillation

• A means of separating substances in a mixture or solution by differences in their boiling points.

Chemical properties

• Flammability : a materials ability to burn in the presence of oxygen

• Reactivity : how easily a chemical reacts with other substances.

• Health : degree of danger to humans

Signs of a chemical reaction

1. Change in color

2. Production of a gas

3. Formation of a precipitate

Assignment:

Pages 63-64

1-10,12,15,26,27

Page 65

1-6