Chapter 2: Matter

Section 3: Properties of Matter

A. Physical Property

1. Physical property is anything that can be seen or measured without changing the make up of a substance.

a. Examples: Boiling point, freezing point, weight, color, odor, hardness, density, magnetic, etc.

2. Physical properties are observed by using the senses.

a. See, hear, touch, taste, smell

3. No two substances have exactly the same properties.

4. Physical Properties are used to separate mixtures.

a. Sand and marbles: pick out the marbles

b. Sand and Iron fillings: use a magnet.

5. Density is a physical property.

a. Density is a measure of the physical mass of an object divided by its volume.

b. Measured in grams/cubic cm. (g/cm3)

c. Avg. density of liquid water is about 1 g/cm3.

d. Oil will float on water!!!

Elemental Sulfur

Chlorine Gas

B. Physical Change

1. Physical change: a process that does not change the chemical composition of a substance; but does change the size, shape, etc.

a. Breaking Glass

b. Cutting Wood

c. Changing States

2. Mixtures and Solutions can be separated by physical means.

a. Salt Water: Boil water and salt will be left.

C. Chemical Properties

1. Chemical properties are characteristics that show HOW a substance reacts to from another substance.

a. Ability to burn is a chemical property!!

b. Corrosion (rusting, oxidizing, etc.) is a chemical property.

2. Why do you think rusting is a chemical property?

a. Is the metal changed into a different substance? (is it as strong????)

b. Does it have different chemical and physical properties because of the rust?

D. Chemical Change

1. Causes a substance to change into a new substance.

2. The new substances has totally different properties.

a. Wood burning: changes wood to ash, gives off heat and light.

b. Steel rusting: iron joins with oxygen causing Iron Oxide to form.

c. Aluminum forming aluminum oxide (similar to rusting)

d. Chemical Changes ALWAYS cause physical changes!!!!

E. Three Specific Chemical Changes

1. Electrolysis: Electricity producing chemical changes.

a. Water separated into hydrogen and oxygen gas.

2. Corrosion: metals chemically changed by combining with other materials. (usually oxygen)

a. Silver tarnishing: silver reacts with water and oxygen.

3. Combustion: materials burning

a. Organic matter contains carbon, hydrogen, and oxygen.

b. C6H12O6 Energy, CO2 & H2O

1. Heat and Light are produced by the atoms rearranging, and forming new compounds

2. C6H12O6 Glucose

3. CO2 Carbon Dioxide

4. H2O Water

F. States of Matter

1. Four physical states of matter

a. Solids, Liquids, Gases, Plasma

2. Each state is determined by amount of energy it contains.

a. Solid: Minimal thermal energy

b. Plasma: highest energy, electrically charged particles.

1. Plasma naturally occurs on the sun and as lightning on Earth.

2. We create plasma in fluorescent lights.

G. Energy levels in States of Matter. 1. Solids: definite shape, definite volume, definite

mass.

2. Liquids: definite volume, definite mass.

a. No definite shape (takes the shape of its container)

3. Gases: No definite shape, no definite volume.

a. Fills entire space it is placed in.

b. Only has definite mass

4. Plasma: like gas has no definite shape or volume.

a. Contains the most energy.

Do not copy…but pay attention!!

Solid

Liquid

Gas

Plasma

**As energy increases…density decreases

**As density increases…energy decreases

H. Kinetic Theory of Matter 1. All matter is made up of tiny particles.

2. The particles are in constant motion.

3. Motion and spacing determine state.

4. Higher temperature; more Kinetic Energy causes faster motion.

5. Kinetic energy: energy of movement.

6. Potential Energy: Energy of rest

a. Remember the demonstration with the tennis ball!!

I. Properties of a Solid 1. Particles are packed very close together.

2. Particles vibrate back and forth but do not change position.

3. Most solids form crystals

a. Particles form a repeating pattern.

b. Ex: Snow, sugar, diamonds

c. Crystals break forming flat sides.

4. Amorphus Solid

a. Particles do NOT form repeating patterns.

b. EX: Glass, butter, wax

J. Properties of a Liquid

1. Particles close together, but free to move around.

a. This allows liquids to flow.

2. VISCOSITY: Describes how fast a liquid can flow.

a. HIGH VISCOSITY= very thick, flows slowly

1. Tar, honey, cold syrup= High viscosity.

b. LOW VISCOSITY= runny, flows quickly

1. Water, gasoline, milk = low viscosity

K. Gases

1. Gases have a lot of energy

2. Particles move freely in a straight line.

3. Mostly empty space between particles.

4. Particles change directions when they enounter obstructions. (they bounce)

L. Plasma

1. Highest energy state of matter.

2. Formed from intense heat or electricity ionizing gas.

3. Ironically it is the most common state in the universe. (because of stars)

4. On Earth, Lightning is the only natural form of plasma

M. Change of State

1. All Changes in state are physical changes

Solid

Solid to Liquid melting point

Liquid to Solid freezing point

Liquid Liquid to Gas evaporation point

Gas to Liquid condensation point

Gas Temp at which a liquid boils: boiling point

SAME

Temp

SAME

Temp

N. Change of State Special Case:

1. Sublimation: when a solid goes directly to a gas without becoming a liquid

Or

2. A gas becoming a solid without being a liquid

a. Examples: Frost, snow, dry ice