Transcript Chapter 1 Chemistry: The Study of Matter

Chapter 1
Matter and Change
pp. 4- 27
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Ch. 1 - Matter
I. Introduction
(p.5-7)
What is Chemistry?
Branches of Chemistry
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What is Chemistry?
 The
study of the composition,
structure, and properties of matter
and the changes it undergoes.
 Chemistry is a physical science.
 A basic understanding of chemistry
is central to all other sciences.
 Chemistry is also central to our
everyday lives.
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Branches of Chemistry
 Inorganic
Chemistry - study of
substances without carbon
 Organic Chemistry - study of all
substances containing carbon
 Biochemistry- study of the
chemistry of living organisms
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Ch. 1 - Matter
II. Classification of Matter
(p.15-17, 397-398)
– Classifying Matter by
Composition
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Classifying Matter by Composition
Homogeneous – matter with a
uniform composition
Heterogeneous - matter without a
uniform composition
Substance- A pure type of matter
that does not vary from sample to
sample. Includes elements and
compounds
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Classifying Matter by Composition
Elements- simplest kind of matter, made
of one type of atom
 An atom is the smallest unit of an
element that maintains the properties of
that element.
 Cannot be broken down into simpler
substances by ordinary chemical means
 Ex. gold, copper, oxygen (on the
periodic table)

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Elements are Pure Substances

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Element
– composed of identical atoms
– EX: copper wire, aluminum foil
Classifying Matter by Composition
Compounds – matter composed of the
atoms of two or more elements
chemically bonded
 Compounds can be broken down by
chemical methods
 When they are broken down, the
components have completely different
properties than the compound.
 Ex. Sugar, salt, water, carbon dioxide

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Compounds are Pure Substances

Compound
– composed of 2 or more
elements in a fixed ratio
– properties differ from those
of individual elements
– EX: table salt (NaCl)
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Classifying Matter by Composition
A mixture is a blend of two or more
kinds of matter, each of which retains its
own identity and properties.
 A mixture is mixed together physically.
 Variable composition, often expressed
by a percent composition by mass or
volume (Ex. 5% salt and 95% water)

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Classifying Matter by Composition
A heterogeneous mixture is not the
same throughout (not uniform).
 Examples: M & M’s, Chocolate chip
cookie, gravel, soil, rocks such as
granite, blood, milk, salad, ocean
water, etc.


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Homogeneous mixtures are also called
solutions. Ex. Salt water and Kool –aid
Mixtures

Variable combination of 2 or more
pure substances.
Heterogeneous
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Homogeneous
Mixtures

Solution
– homogeneous
– very small particles
– no Tyndall effect
– particles don’t settle
– EX: rubbing alcohol
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Tyndall Effect
Mixtures

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Colloid
– heterogeneous
– medium-sized particles
– Tyndall effect
– particles don’t settle
– EX: milk
Mixtures

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Suspension
– heterogeneous
– large particles
– Tyndall effect
– particles settle
– EX: fresh-squeezed
lemonade
Mixtures

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Examples:
– mayonnaise
colloid
– muddy water
suspension
– fog
colloid
– saltwater
solution
– Italian salad
dressing
suspension
Classify It

Examples:
– magnesium
– Pizza
– Calcium chloride
– Orange juice
– Club soda
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Classify It

Examples:
– magnesium
element
– pizza
hetero. mixture
– Calcium
compound
chloride
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– Orange juice
hetero. mixture
– Club soda
Homo. (solution)
Composition of Matter Flowchart
MATTER
yes
MIXTURE
yes
Is the composition
uniform?
Homogeneous
Mixture
(solution)
no
Can it be physically
separated?
PURE SUBSTANCE
no
Heterogeneous
Mixture
yes
Can it be chemically
decomposed?
Compound
no
Element
Classifying at the Molecular Level
Mixture
Element
Compound
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Ch. 1 - Matter
III. States of Matter (p.12)
– Classifying Matter by the Kinetic
Molecular Theory
– States of Matter
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Classifying Matter by Kinetic
Molecular Theory

KMT
– Particles of matter are always in
motion.
– The kinetic energy (speed) of these
particles increases as temperature
increases.
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Four States of Matter

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Solids
– very low KE - particles
vibrate but can’t move
around
– fixed shape
– fixed volume
Four States of Matter

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Liquids
– low KE - particles can
move around but are
still close together
– variable shape
– fixed volume
Four States of Matter

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Gases
– high KE - particles can
separate and move
throughout container
– variable shape
– variable volume
Four States of Matter

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Plasma
– very high KE - particles collide with
enough energy to break into
charged particles (+/-)
– gas-like, variable
shape & volume
– stars, fluorescent
light bulbs, CRTs
States of Matter
Definite Definite Particle position
Volume? Shape? and movement
Solid
Liquid
Gas
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YES
YES
NO
YES
Packed tightly,
vibrate about fixed pt
NO
Close together, can
move past each
other - flow
NO
Far apart, move
rapidly - flow
Ch. 1 - Matter
IV. Properties & Changes in Matter
(p.11-14)
– Extensive vs. Intensive
– Physical vs. Chemical
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Extensive vs. Intensive

Extensive Property
– depends on the amount of matter
present

Intensive Property
– depends on the identity of substance,
not the amount
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Extensive vs. Intensive

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Examples:
– boiling point
intensive
– volume
extensive
– mass
extensive
– density
intensive
– conductivity
intensive
Physical vs. Chemical

Physical Property
– can be observed without changing the
identity of the substance

Chemical Property
– describes the ability of a substance to
undergo changes in identity
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Physical vs. Chemical

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Examples:
– melting point
physical
– flammable
chemical
– density
physical
– magnetic
physical
– tarnishes in air
chemical
Physical vs. Chemical

Physical Change
– changes the form of a substance
without changing its identity
– properties remain the same

Chemical Change
– changes the identity of a substance
– products have different properties
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Physical Changes in Matter
Condense
Freeze
Evaporate
Melt
Solid
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Liquid
Gas
Physical Changes in Matter

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Sublimation is a process in which a
solid changes directly to a gas without
going through the solid phase.
Physical vs. Chemical

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Examples:
– rusting iron
chemical
– dissolving in water
physical
– burning a log
chemical
– melting ice
physical
– grinding spices
physical
Indications of chemical
change
1 Production of heat, light,
sound, or electricity
2.) Production of a gas
3.) Formation of a precipitate
4.) A change in color
5.) A change in odor
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Separating Mixtures
Mixtures are separated by their
physical properties.
Primary methods of separating
mixtures are:
filtration
distillation
centrifuge
chromatography
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Separating Mixtures
Filtration
is a method
used to separate the
components of mixtures
that contain an insoluble
solid and a liquid.
Example: sand and water
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Separating Mixtures
Distillation
is a method of
separating substances in a
mixture by evaporation of a
liquid and subsequent
condensation of its vapor.
Example: desalination of salt
water
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Separating Mixtures
Centrifuge (see p. 16)
Used to separate solid-liquid
mixtures such as those in
blood. The centrifuge spins
rapidly and causes the solid
to settle to the bottom.
Ex. Separating blood
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Separating Mixtures
Chromatography is a method of
separating mixtures that uses a
stationary phase and a mobile
phase. Paper chromatography
can be used to separate
pigments because they move at
different rates on the paper.
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Ch. 1 - Matter
V. Elements
(p.20-24)
– Extensive vs. Intensive
– Physical vs. Chemical
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Elements
 There
are 92 naturally occurring
elements
 Each has a 1 or two letter
symbol
 First letter always capitalized
second letter is lower case
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Elements
 The
periodic table shows the
elements organized by their
chemical properties
 Columns on the table represent
groups or families of elements with
similar chemical properties
 Properties vary across the
horizontal rows or periods
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Elements
Three general classes of
elements are metals, nonmetals,
and metalloids. Metals are on
the left and in the center of the
periodic table. Nonmetals are
on the right. Metalloids are on
the zig-zag dividing line.
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Metals
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Nonmetals
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Semi-metals or Metalloids
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Noble Gases
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Properties of metals
Metals have certain properties:
shiny luster, reflect heat and
light, ductile, malleable,very
tensile, good conductor of
heat and electricity.
All metals except mercury are
solids at room temperature.
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Properties of nonmetals
Nonmetals have certain
properties:
 poor conductor of heat and
electricity, dull luster and brittle
if solids, many nonmetals are
gases.
Bromine is a dark red liquid.
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Properties of metalloids
Metalloids
have properties of
metal and nonmetals,
they are semiconductors,
they are all solids.
Metalloids are B, Si, Ge, As,
Sb, Te, Po, and At
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Elements
Noble gases (Group 18) are
nonmetals that are
essentially non-reactive
elements. They are gases
at room temperature
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Elements to memorize
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
Quiz # 1 – Symbols and correct spelling
for elements # 1-46

Quiz #2 - Symbols and correct spelling
for elements # 47-92