Starter: Write Down What Type of Change?

Starter: Write Down What Type of Change?

III. Classification of Matter (pp. 80-87)

Matter FlowchartPure SubstancesMixtures

III. Classification of Matter (pp. 80-87)

Matter FlowchartPure SubstancesMixtures

A. Pure SubstancesA. Pure Substances Element

composed of identical atoms EX: copper wire, aluminum foil

Element composed of identical atoms EX: copper wire, aluminum foil

A. Pure SubstancesA. Pure Substances

Compound

composed of 2 or more elements in a fixed ratio

properties differ from those of individual elements

EX: table salt (NaCl)

Compound

composed of 2 or more elements in a fixed ratio

properties differ from those of individual elements

EX: table salt (NaCl)

B. MixturesB. Mixtures

Variable combination of 2 or more pure substances.

Variable combination of 2 or more pure substances.

Heterogeneous Homogeneous

B. MixturesB. Mixtures

Solution homogeneous very small particles particles don’t settle EX: rubbing alcohol

Solution homogeneous very small particles particles don’t settle EX: rubbing alcohol

B. MixturesB. Mixtures Heterogeneous

medium-sized to large-sized particles

particles may or may not settle

EX: milk, fresh-squeezed

lemonade

Heterogeneous medium-sized to

large-sized particles

particles may or may not settle

EX: milk, fresh-squeezed

lemonade

B. MixturesB. Mixtures

Examples: tea

muddy water

fog

saltwater

Italian salad dressing

Examples: tea

muddy water

fog

saltwater

Italian salad dressing

Answers: Solution

Heterogeneous

Heterogeneous

Solution

Heterogeneous

Answers: Solution

Heterogeneous

Heterogeneous

Solution

Heterogeneous

C. Matter FlowchartC. Matter Flowchart

MATTER

Can it be physically separated?

Homogeneous Mixture

(solution)

Heterogeneous Mixture Compound Element

MIXTURE PURE SUBSTANCE

yes no

Can it be chemically decomposed?

noyesIs the composition uniform?

noyes

C. Matter FlowchartC. Matter Flowchart

Examples: graphite

pepper

sugar (sucrose)

paint

soda

Examples: graphite

pepper

sugar (sucrose)

paint

soda

element

hetero. mixture

compound

hetero. mixture

solution

D. Physical vs. Chemical PropertiesD. Physical vs. Chemical Properties

Examples: melting point

flammable

density

magnetic

tarnishes in air

Examples: melting point

flammable

density

magnetic

tarnishes in air

physical

chemical

physical

physical

chemical

E. Physical ChangesE. Physical Changes

Physical Change changes the form of a substance without

changing its identity

properties remain the same

Examples: cutting a sheet of paper, breaking a crystal, all phase changes

Physical Change changes the form of a substance without

changing its identity

properties remain the same

Examples: cutting a sheet of paper, breaking a crystal, all phase changes

F. Chemical ChangesF. Chemical Changes Process that involves one or more

substances changing into a new substance Commonly referred to as a chemical reaction New substances have different compositions

and properties from original substances

Process that involves one or more substances changing into a new substance Commonly referred to as a chemical reaction New substances have different compositions

and properties from original substances

F. Chemical ChangesF. Chemical Changes

Signs of a Chemical Change

change in color or odor

formation of a gas

formation of a precipitate (solid)

change in light or heat

Signs of a Chemical Change

change in color or odor

formation of a gas

formation of a precipitate (solid)

change in light or heat

G. Physical vs. Chemical ChangesG. Physical vs. Chemical Changes

Examples: rusting iron

dissolving in water

burning a log

melting ice

grinding spices

Examples: rusting iron

dissolving in water

burning a log

melting ice

grinding spices

chemical

physical

chemical

physical

physical

Chemical ReactionsChemical Reactions

There are four clues that provide evidence of a chemical change:

1. Transfer of energy

2. Change in color

3. Production of a gas

4. Formation of a precipitate

There are four clues that provide evidence of a chemical change:

1. Transfer of energy

2. Change in color

3. Production of a gas

4. Formation of a precipitate

Chemical ReactionsChemical 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?

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 MassLaw 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.

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.