Matter… has mass and occupies space. Mass is the amount of matter an object contains. Mass...

Matter…

has mass and occupies space. Mass is the amount of matter an object contains. Mass never changes, but weight does.

The States of Matter

Matter exists in three states: Solid: a rigid substance with a definite shape Liquid: has a definite volume but takes the shape

of its container Gas: takes the shape and volume of its container

Matter can be classified as a mixture or a pure substance.

- Only one substance- Uniform and definite composition- All samples have identical physical properties

- Two or more substances mixed together- Indefinite composition- Can be physically separated into pure substances

- Only one type of element- Cannot be chemically separated into simpler substances

- More than one type of element chemically bonded together- Can be chemically separated into elements

Glucose

C6H12O6

CO2

H2H2O

FePb

Elements…

• contain only one type of atom

Each element has a name and a symbol.

The symbol usually consists of the first one or two letters of the element’s name.

Sometimes the symbol is taken from the element’s original Latin or Greek name.

Examples: oxygen O krypton Kr

Examples: gold Au aurum lead Pb plumbum

Compounds

• Compounds are substances that contain two or more different types of elements.

In general, the properties of compounds are quite different from those of their component elements.

Example:

Table salt is NaCl (sodium + chlorine), while sodium (Na) is a soft metal that acts explosively with water and chlorine (Cl) is a pale yellow- green poisonous gas

- Solutions(one phase)- Looks the same throughout- Uniform composition- Evenly mixed

- Suspensions(two phases)- Looks different throughout (chunks)- Not uniform in composition- Will usually settle over time

Muddy water

Tea Steel

Saltwater

Sample Problem – 1.1 Classify each of the following as an element, a compound, or a mixture:

a. spaghetti sauceb. milk shakec. table sugard. river watere. airf. nitrogen

Sample Problem – 1.2Which of the following are …homogeneous? …heterogeneous?

spaghetti sauce glass muddy water cough syrup

Separating Mixtures

Mixtures can be separated into pure substances by various means.

Separation of Mixtures

• Distillation – a liquid is boiled to produce a vapor that is then condensed again to a liquid.

•

Separation of Mixtures

filtration

Physical Properties

Any characteristic of a substance that can be observed or measured without changing the composition of the substance.

Ex: density, viscosity, melting point, boiling point, taste, hardness, color, odor

Chemical Properties –

describe a substance’s ability to change to a different substance.

Ex. burning, rusting, decomposing, fermenting, exploding and corroding

Intensive property- does not depend on the size of the system or the amount of material in the system.Examples- temperature, color, hardness, melting point, pressure and density

Extensive property- directly proportional to the amount of material in the system.Examples- mass, volume, length and total charge

Physical Change

A physical change involves a change in one or more physical properties but no change in composition.

The original substance is still the same material.

Liquid

Water

Water

VaporSolid

Water

Water is still H2O in all phases. Therefore, phase changes are physical changes!

Chemical Change

A chemical change transforms a substance into one or more new substances.

Cutting Wood

Burning Wood

Rain (water vapor => liquid water)

Melting Gold

Rust

Molding Bread

Chewing apple

Digestingapple

Sparkler

Dissolving Kool-Aid powder in water

Simplifying Mixtures and Compounds

The separation of a mixture is a physical change (such as distillation, filtration).

Breaking down a compound into simpler substances is a chemical change (such as decomposition).

Sample Problem – 1.3

Describe how a mixture of iron filings and aluminum filings can be separated. Is this process a physical or chemical change?

Sample Problem – 1.4

What physical properties could be used to separate a mixture of iron filings and salt?

Sample Problem – 1.5

State several physical or chemical properties that could be used to distinguish between each of the following pairs of substances.

a. gasoline and waterb. copper and silverc. water and salt water solutiond. aluminum and steel

Law of Conservation of Mass

Mass is neither created nor destroyed in a chemical or physical process.

reactants products

Mass reactants = Mass products

“What goes in, must come out!”

Mass of Reactants(before reaction)

Mass of Products(after reaction)

Reaction occurs

Notice the mass before and after the reaction are the same.

Law of Conservation of Mass

hydrogen + oxygen water

How much water is produced when 4.8 grams of hydrogen reacts completely with 38.4 grams of oxygen?

(Answer: 43.2 grams)

Summary: The Organization of Matter