Chemistry is the study about how matter
is put together, how atoms combine to
form molecules, and how the molecules
combine to make up the many kinds of
matter around us.
 Math- the language of Science: 16th century-Science
made huge progress when it was discovered that
nature can be analyzed and described when
scientific findings are expressed mathematically they
are easy to verify or disprove be experiment
 Galileo Galilei (1564-1642) Italian Physicist
 Francis Bacon (1561-1626) English philosopher
 Co-Founders of scientific method ~ Extremely
effective in gaining, organizing, and applying new
knowledge
Scientific method – systematic approach to do
research, answer questions, and solve problems
 Recognize a problem
 Make an educated guess-a hypothesis-about the
answer
 Predict the consequences of the hypothesis
 Perform experiments to test predictions
 Formulate the simplest rule that organizes the
main ingredients: hypothesis, prediction, and
experimental outcomes
 http://www.youtube.com/watch?v=zrzMhU_4m-g
Classification of Matter
 Matter – anything that has mass and takes up
space
 Mixture- matter that contains two or more
different materials
 Phase- any region with a uniform set of properties
Ex: milk, watery part is one phase while fat is
the second phase
Mixtures are divided into two
categories
 1. Heterogeneous
mixture- a
mixture that is
composed of
more than one
phase
 Ex: milk, granite,
sand
 2. Homogeneous mixturematerials that consist of only
one phase.
 If you break a piece of
homogeneous matter into
smaller pieces, each piece
will have the same properties
as every other small piece
 Ex: seawater, window glass,
and air
 Substances- homogeneous materials that
always have the same composition
 *Homogeneous mixtures are not pure
substances, yet the substances that comprise
them are evenly dispersed throughout the
mixture
Pure Substances are divided into
two categories
 1. Elementssubstances composed
of only one kind of
 2. Compoundscomposed of more
than one kind of atom
atom (elements on the
P.T.)
 Ex: sodium ~ Na, Iron
~ Fe, Neon ~ Ne
(made from multiple
elements on the P.T.)
 Ex: water ~ H2O, table
salt ~ NaCl
Changes in Properties
 Physical change- same substance remains after a
change has taken place
 *Pounding, pulling, or cutting does not change
the chemical character of a substance. Cutting a
piece of wood into smaller pieces, tearing paper,
dissolving sugar in water, hammering copper
into a new shape are all examples of physical
change.
 Physical properties- a description of the behavior of
a substance undergoing a physical change two kinds
 1. Extensive- depends on the amount of matter
present
 Ex: mass, length, volume
 2. Intensive- does not depend on the amount of
matter present
 Ex: density (regardless of size, each sample of a
substance has the same density) color, crystalline
shape, melting point, boiling point, and refractive
index (ability of material to bend light)
 Chemical change- after
a change has taken
place a new substance
appears
 Changes that
produce a new kind
of matter with
different properties.
Burning, digestion,
fermenting all form
new substances with
different
characteristics.
 Sodium- a silvery, soft
metal that reacts
vigorously with water
(Na)
 Chlorine- a yellow-green
gas that is highlycorrosive and poisonous
(Cl)
 Yet if these two elements
are brought together,
they combine to form a
white crystalline solid.
Table salt (NaCl), which
neither reacts with water,
nor is poisonous.
1. Heat and/or light is produced
2. Production of a gas
3. Color change
4. Formation of a precipitate – a cloudy
solid which appears after mixing to clear
solutions
Intro to the Periodic Table
Vertical columns
Horizontal rows
 called groups or
families.
 called periods.
 Elements in a group
have similar chemical
& physical properties.
 Numbered from 1-18
from left to right
 Elements within a
period have
properties that
change progressively
across the table.
 Metals – (left side) are good conductors of heat and
electricity; shiny metallic luster (mostly silver or grayish
white); malleable (hammered or rolled into thin sheets);
ductile (string into a wire); properties vary according to
groups
 Nonmetals – (right side) elements that are poor
conductors of heat and electricity, dull (no luster); some
are gases at room temperature. Br is a liquid; C, P, Se, S & I
are solid and much more brittle than metals
 Metalloids – (on the stair-step line) – elements that have
characteristics of both metals and nonmetals to a limited
degree. Less malleable than metals, but not as brittle as
nonmetals; some have luster, some don’t; semiconductors
of electricity (used in semi-conducting materials found in
computers, calculators, watches, TV’s and radios)
Branches of Chemistry
 Organic Chem – study of carbon – containing compounds
 Inorganic Chem – all substances not classified as organic
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(mainly those that do not contain carbon)
Physical Chem – the study of properties and changes of
matter and their relation to energy
Analytical Chem – identification of the components and
composition of materials
Biochemistry – substances and processes occurring in
living things
Theoretical Chem – uses math and computers to
understand the principles behind observed chemical
behavior and to design and predict new compounds