Chapter 3 Matter

I. Properties & Changes in Matter

 Extensive vs. Intensive  Physical vs. Chemical

A. Extensive vs. Intensive



Extensive Property

 depends on the amount of matter present 

Intensive Property

 depends on the identity of substance, not the amount

A. Extensive vs. Intensive



Examples:

 boiling point  volume  mass  density  conductivity intensive extensive extensive intensive intensive

B. Physical vs. Chemical



Physical Property

 can be observed without changing the identity of the substance  Click for movie 

Chemical Property

 describes the ability of a substance to undergo changes in identity

B. Physical vs. Chemical



Examples:

 melting point  flammable  density  magnetic  tarnishes in air physical chemical physical physical chemical

B. Physical vs. Chemical



Physical Change

 changes the form of a substance without changing its identity  properties remain the same

Chemical Change

changes the identity of a substance products have different properties

B. Physical vs. Chemical



Signs of a Chemical Change

 change in color or odor  formation of a gas  formation of a precipitate (solid)  change in light or heat

B. Physical vs. Chemical



Examples:

 rusting iron  dissolving in water  burning a log  melting ice  grinding spices chemical physical chemical physical physical

Chemical verses physical change Which one is a physical change?

A. Sodium reacting B. Iodine changing with chlorine. from a solid to a gas

Matter

II. States of Matter

 Kinetic Molecular Theory  States of Matter  Click for movie

Physical Properties

States of matter

solid liquid gas

A. Kinetic Molecular Theory



KMT

 Particles of matter are always in motion.

 The kinetic energy (speed) of these particles increases as temperature increases.

B. Four States of Matter



Solids

 very low KE - particles vibrate but can’t move around  fixed shape  fixed volume

B. Four States of Matter



Liquids

 low KE - particles can move around but are still close together  variable shape  fixed volume

B. Four States of Matter



Gases

 high KE - particles can separate and move throughout container  variable shape  variable volume  Click for movie

The States of Matter FREEZING VAPORIZATION MELTING CONDENSATION

Changes of State



Melting - the transition from the solid substance into a liquid

 The melting Point 

Freezing or Fusion - liquid to solid

 The Freezing point 

When does water melt?



When does water freeze?

Changes of State



Boiling or Vaporization or Evaporation

 liquid to gas 

Condensation - gas to liquid



Sublimation - solid to gas



Deposition - gas to solid

B. Four States of Matter



Plasma

 very high KE - particles collide with enough energy to break into charged particles (+/-)  gas-like, variable shape & volume  stars, fluorescent light bulbs, CRTs

Matter

III. Classification of Matter

 Matter Flowchart  Pure Substances  Mixtures

A. Matter Flowchart yes MATTER no

Can it be physically separated?

PURE SUBSTANCE MIXTURE yes Is the composition uniform?

Homogeneous Mixture (solution) no Heterogeneous Mixture yes

Can it be chemically decomposed?

Compound Element no Colloids Suspensions

A. Matter Flowchart



Examples:

 graphite  salt & pepper  sugar (sucrose)  paint  soda element hetero. mixture compound hetero. mixture solution

B. Pure Substances



Element

 composed of identical atoms  Ex: copper wire, aluminum foil

B. Pure Substances



Compound

 composed of 2 or more elements in a fixed ratio  properties differ from those of individual elements  Ex: table salt (NaCl)

B. Pure Substances



Law of Definite Composition

 A given compound always contains the same, fixed ratio of elements.



Law of Multiple Proportions

 Elements can combine in different ratios to form different compounds.

B. Pure Substances

 For example… Two different compounds, each has a definite composition.

C. Mixtures

 Variable combination of 2 or more pure substances.

Heterogeneous Homogeneous

C. Mixtures



Solution

 homogeneous  very small particles  no Tyndall effect  particles don’t settle  EX: rubbing alcohol Tyndall Effect

C. Mixtures



Colloid

 heterogeneous  medium-sized particles  Tyndall Effect  particles don’t settle  EX: milk

C. Mixtures



Suspension

 heterogeneous  larger particles  Tyndall Effect  particles settle  EX: fresh-squeezed lemonade with pulp

Heterogeneous Mixtures



Heterogeneous mixtures occur when you can see the physical differences between the substances.



Is a salt and water mixture a heterogeneous mixture?



Is a mixture of sand and water a heterogeneous mixture?

Rubbing Alcohol Oil Corn syrup

C. Mixtures



Examples:

 milk  muddy water  fog  salt & water  Italian salad dressing colloid suspension colloid solution suspension

Physical Separation Techniques



Mixtures are combinations of two or more substances that when mixed do not change.



Therefore, physical properties can be used to separate them.



What physical properties could be used?



Think about how you could separate iron, salt and sand.

 Total Cereal

Physical Separations

 Filtering  Separation by the physical property of solubility. One substance is soluble the other is not.

 Coffee filters  Tea bags  Spaghetti

Physical Separations

 Chromatography  Separation by solubility, mass or bonding properties 

Separation of inks



Separation of M&M dyes



Separation of leaf pigments.

Physical Separations

 Distillation  Separation by the physical properties of melting point or boiling point  Purifying water