Download Chapter 3 Classification of Matter

Chapter 3
Classification of
Matter
Objectives:
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?
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Anything that has mass and occupies space
 Composed of atoms
Exists in three states on earth
 Solid
 Liquid
 Gas
Exists in fourth state in space
 Plasma
Solids
Definite shape and volume
 Particles tightly packed
 Crystalline – salt, sugar,
quartz
 Amorphous solids – no
regular, geometric
pattern

Liquids
Definite volume
 Not a definite shape
(Takes shape of container)
 Particles have more energy
 Particles can move freely

Gases
Indefinite volume
 No definite shape
 Particles have high energy
level
 Particles move
independently of one
another

Substances and Mixtures

Pure Substance: a particular kind of
matter with a definite, fixed composition
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Elements (copper, gold, oxygen)
Compounds (sugar, salt, water)
Mixture: a blend of two or more pure
substances

Not chemically combined
Matter
Pure substances
(homogeneous composition)
Elements
Mixtures of two or
more substances
Compounds
Solutions
(homogeneous composition
– one phase)
Figure 3.2 (page 48)
Heterogeneous
mixtures
(two or more phases)
Types of Mixtures

Heterogeneous mixtures
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Visibly different parts
Chocolate chip cookies; granite
Two or more phases (usually)
Homogeneous mixtures
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Different parts not visible (uniform
throughout)
One phase
Seawater; air
Separating Mixtures

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Do NOT cause chemical changes
Heterogeneous Mixtures

Filtration
Separating Mixtures

Homogeneous Mixtures

Distillation
Separating Mixtures

Homogeneous Mixtures

Chromatography
Separating Mixtures

Homogeneous
Mixtures

Crystallization
Pure Substances

Elements

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A substance that cannot be separated into
simpler substances
Compound

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Two or more elements combined through a
chemical reaction
Different properties than elements which
compose it
Elements
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~111 presently known elements
Building blocks of all substances
At room temperature:

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2 liquid
11 gases
All others solid
Figure 3.3 – distribution of elements in
galaxies, earth’s crust, seawater and air, and
human bodies
Elements

Names of the elements

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Greek
Latin
German
Properties of elements
Scientist who discovered it
Location where discovered
Elements


Arranged in the Periodic Table (inside
front cover)
Symbols

One or two letters


Usually part of name (Table 3.3, pg 52)
Some symbols are Latin/Greek name
(Table 3.4, pg 52)
Elements

Classificiation

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
Metal
Nonmetal
Metalloid
See Table 3.5
(page 54)
Elements

Metals:
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Usually solid at room temperature
Good conductors of heat and
electricity
High luster
Ductile
Malleable
High melting point; high density
Usually don’t combine with each other
Readily combine with nonmetals
Elements

Nonmetals:
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Solids (C, P, S, Se, I); Liquid
(Br); Gases (all others)
Poor conductors of heat and
electricity; no luster
Low melting point; low density
Will combine with each other
(CO2)
Will combine with metals or
metalloids
Some found uncombined in
nature (noble gases)
Elements
 Metalloids
Have properties of
both metals and
nonmetals
 Some used for
semiconductors in
electronics

Compounds

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Two or more elements
chemically combined
New properties
Definite proportions
Can be chemically
separated
Molecular or Ionic
Compounds
 Molecular
Held together with covalent bonds
 Molecule: smallest uncharged
individual unit of a compound
 Water is an example

Compounds
 Ionic

Ion: positively or negatively charged
atom or group of atoms
Cation – positive
 Anion – negative

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Held together by ionic bond –
attraction between positive and
negative charges
Compounds
 Diatomic
Molecules
Always only 2 atoms
 7 naturally occurring

Hydrogen, oxygen, nitrogen, flourine,
chlorine, bromine, iodine
 H2, O2, N2, F2, Cl2, Br2, I2,

Chemical Formulas
 Abbreviations
for compounds
 Symbols and ratios of atoms
 Sodium Chloride (NaCl)
1 atom of sodium for every 1 atom of
chlorine
 Number 1 not usually written

Chemical Formulas
 Subscript
present
indicates # of atoms
H2O has 2 Hydrogen atoms and 1
Oxygen atom
 H2SO4 has 2 hydrogen atoms, 1 sulfur atom, 4 oxygen atoms
 NaOH has 1 sodium atom, 1 oxygen atom, 1 hydrogen atom
6 carbon atoms, 12 hydrogen atoms,
 C6H12O6 has and 6 oxygen atoms

Chemical Formulas
 Parentheses
are used to show
when a compound contains more
than one group of atoms that
occurs as a unit

Calcium Nitrate
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Ca(NO3)2 has 1 calcium, 2 nitrogen,
and 6 oxygen atoms
Ba3(PO4)2 has
3 barium, 2 phosphorus, and 8 oxygen atoms
Chemical Formulas
 Show
only number and kind of
atom
 Do not show arrangement of the
atoms or how chemically bonded