Chapter 3Classification of

MatterObjectives:

Define and give examples of 3 states of matter (3.1 & 3.2)Distinguish between substances and mixtures (3.3 & 3.12)Understand what elements are (3.4-3.7)Distinguish between metals, nonmetals and metalloids (3.8)Define compounds and diatomic molecules (3.9 & 3.10)Be able to write chemical formulas (3.11)

What is Matter?What is Matter? Anything that has mass and occupies space

Composed of atoms Exists in three states on earth

Exists in fourth state in space

Solids Definite Particles tightly packed Crystalline –

Amorphous solids –

Liquids Definite volume Not a

Particles have Particles can

Gases Indefinite volume No Particles have

Particles

Substances and Mixtures Pure Substance: a particular kind of

matter with a definite, fixed composition

Mixture:

Matter

Pure substances (homogeneous composition)

Mixtures of two or more substances

Elements Compounds

Solutions (homogeneous

composition – one phase)

Heterogeneous mixtures

(two or more phases)

Figure 3.2 (page 48)

Types of Mixtures Heterogeneous mixtures

Chocolate chip cookies; granite

Homogeneous mixtures

Separating Mixtures Do NOT cause chemical

changes Heterogeneous Mixtures

Separating Mixtures Homogeneous Mixtures

Separating Mixtures Homogeneous Mixtures

Separating Mixtures Homogeneous

Mixtures

Pure Substances Elements

Compound

Elements ~111 presently known elements

At room temperature:

Figure 3.3 – distribution of elements in the

Elements Names of the elements

Greek Latin Location where discovered

Elements Arranged in the Periodic Table (inside

front cover) Symbols

Some symbols are Latin/Greek name (Table

3.4)

Elements Classification

Metal Nonmetal Metalloid

See Table 3.5

Elements Metals:

Usually solid at room temperature

High luster Malleable Usually don’t combine with each

other

Elements Nonmetals:

Solids ( ); Liquid ( ); Gases (all others)

Poor conductors

Low melting point; Will combine Will combine

Some found uncombined in nature

Elements Metalloids

Have properties of

Some used for semiconductors in electronics

Compounds Two or more elements

New properties Can be chemically

separated

Compounds Molecular

Held together with Molecule:

Water is an example

Compounds Ionic

Ion:

Cation – Anion –

Held together by ionic bond –

Compounds Diatomic Molecules

Always only 2 atoms 7 naturally occurring

Chemical Formulas Abbreviations for compounds Sodium Chloride (NaCl)

Chemical Formulas Subscript indicates # of

atoms present H2O has 2 Hydrogen atoms and 1

Oxygen atom NaOH has

Chemical Formulas Parentheses are used to show

when a compound contains more than one group of atoms that occurs as a unit

Chemical Formulas Show only number and kind

of atom Do not show arrangement of

the atoms or how chemically bonded