The

Classification of

Matter:

Atoms, Elements,

Molecules and

Compounds

Chemistry:

The study of matter and its changes

Matter:

Anything that has mass and volume

Atom:The basic unit of matter

Element:A type of atom

Each element has a name and symbol:

Not all elements are equally common

Kinetic Molecular Theory

Matter is made of tiny particles called atoms, which combine to form molecules.

Molecule:

A group of atoms held together by sharing electrons (covalent bonds)

Compound:A substance containing more than one

element.

Examples:

• Atom, Element, Molecule, Compound:

Four different molecules:

• Which are compounds?

Some molecules are more complex:Some fat molecules: A protein

molecule:

cholesterol

What are each of these?

Atom,

Element,

Molecule,

or

Compound

Allotropes• One of several different forms of an element

O2

Diatomic Oxygen

Molecule

OMonatomic

Oxygen(Single

Oxygen Atom)

O3

OzoneMolecule

Oxygen has 3 allotropes:

Allotropes of Carbon

Carbon NanotubesFullerenes

GraphiteDiamond

All are pure carbon; each has a different molecular or crystalline form.

Practice with Vocabulary:

Molecules can be represented many ways:

Chemical Formula:

Structural Formula:

CH4 H2O

Ball and Stick Model:

Space Filling Model:

HH

O

Chemical Formula:

• All molecules can be represented by a

H2O

subscript

Chemical Formulas show how many atoms of each element are in one molecule:

6234C6H12O4Cl

3123C3H8O

032H2O

021O2

# of Carbon atoms

# of atoms total

# of elements

Chemical Formula

How many atoms of each element are present in one

molecule of:

(NH4)2SO3N…………….H……………S…………….O……………

2813

(NH4)2SO32813

How many atoms of each element are present in one

molecule of:

(NH4)2SO32813

How many atoms of each element are present in one

molecule of:

(NH4)2SO32813

The

Classification

of Matter:Pure Substances

and Mixtures

Pure Substance:= An element or a compound

(Any substance that can be described

by a single chemical formula)

Mixture:

A substance that contains

more than one pure substance

Pure Substance:= An element or a compound

(Any substance that can be described

by a single chemical formula)

Mixture:

Pure Substance:= An element or a compound

(Any substance that can be described

by a single chemical formula)

A substance that contains

more than one pure substance

Mixture:

Pure Substance:= An element or a compound

(Any substance that can be described

by a single chemical formula)

Pure Substance or Mixture?

Pure Substances:

• Are made of only one compound or one element.

• Can be represented by one chemical formula. Examples:

Salt

NaCl

Copper

Cu

Water

H2O

Pure Substances:Pure Substances:Pure Substances:Pure Substances:

Salt

Pure Substances:

Salt

Pure Substances:Pure Substances:

CopperSalt WaterCopperSalt WaterCopperSalt

Anything that contains more than one pure substance.

Mixture:

Examples:

Juice, Granite, Salad Dressing, etc…

Anything that contains more than one pure substance.

Mixture:

Examples:

Anything that contains more than one pure substance.

Mixture:

Juice, Granite, Salad Dressing, etc…

Examples:

Anything that contains more than one pure substance.

Mixture:

Homogenous MixtureAn even mixture; particles are blended

evenly throughout the mixture.

(= “solutions”)

Heterogeneous Mixture:

An uneven mixture;

particles are unevenly distributed.

A. 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

Colloids Suspensions

Pure Substance:A substance that contains

only one type of atom or molecule

Mixture:

A substance that contains

more than one pure substance

Single Chemical Formula:

• All pure substances can be represented by a

H2O

If it’s really a pure substance, you should only need to write ONE chemical formula to describe it’s composition.

Distillation

Vacuum Filtration Electrolysis