Slide 1 ___________________________________ An Introduction to
1 An Introduction to Chemistry
Chemistry
___________________________________ ___________________________________ ___________________________________ ___________________________________ The vibrant colors of the aurora borealis are
the result of chemistry in our atmosphere.
___________________________________ Foundations of College Chemistry, 14th Ed.
___________________________________ Morris Hein and Susan Arena
Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide ___________________________________ Chapter Outline
2 1.1
___________________________________ The Nature of Chemistry
A. Thinking Like a Chemist
1.2
___________________________________ A Scientific Approach to Problem Solving
___________________________________ A. The Scientific Method
1.3
The Particulate Nature of Matter
___________________________________ A. Physical States of Matter
1.4
Classifying Matter
___________________________________ A. Distinguishing Mixtures from Pure Substances
___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 3 ___________________________________ The Nature of Chemistry
___________________________________ Chemistry is the science of matter.
___________________________________ Matter is any object that has mass and occupies space.
___________________________________ Chemistry deals with the composition, structure,
properties, reactions and energetics of matter.
___________________________________ ___________________________________ Chemists devise experiments, interpret data
and synthesize new substances.
___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 4 ___________________________________ Thinking Like a Chemist
Chemists try to understand how and why chemical
changes occur in nature and the human body.
___________________________________ Chemists try to explain the macroscopic world,
which is observable to the eye…
___________________________________ ___________________________________ ___________________________________ ___________________________________ …and the microscopic world, which is made up of objects
too small to see, like atoms and molecules.
© 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 5 ___________________________________ ___________________________________ A Microscopic View of Water
___________________________________ Imagine holding one molecule of water in your hand.
What does it look like?
___________________________________ Water (H2O) is composed of two hydrogen atoms
and one oxygen atom.
___________________________________ The atoms must connect in a specific arrangement,
in this case forming two O-H bonds.
___________________________________ ___________________________________ ___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 6 ___________________________________ A Scientific Approach to Problem Solving
___________________________________ Scientists use a logical process to explain
the world around them.
___________________________________ This process is called the Scientific Method.
___________________________________ ___________________________________ ___________________________________ ___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 7 ___________________________________ The Scientific Method
___________________________________ The Scientific Method
1. Collect the facts and data relevant to your question.
___________________________________ Perform an experiment, then analyze the resulting
data to look for trends that relate to the question.
___________________________________ 2. Formulate a hypothesis.
A hypothesis is a tentative explanation of the data
that requires further experimentation to be validated.
___________________________________ 3. Plan and perform additional experiments to test the
hypothesis.
___________________________________ 4. Modify the hypothesis.
A useful hypothesis must explain all of the data.
© 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 8 ___________________________________ ___________________________________ The Scientific Method
___________________________________ A well-established hypothesis is often called a theory.
A theory summarizes a hypothesis that has been
supported by repeated experimentation. A theory
is valid as long as there is no evidence to disprove it.
___________________________________ A scientific law is a statement of natural phenomenon
where no exceptions are known under the given conditions.
___________________________________ ___________________________________ ___________________________________ ___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 9 ___________________________________ The Particulate Nature of Matter
___________________________________ Matter appears in many forms, both big and small.
On the microscopic level, all matter is composed of
discrete, tiny fundamental particles called atoms.
___________________________________ Using a scanning tunneling microscope, individual atoms
can be configured into specific arrangements.
___________________________________ ___________________________________ ___________________________________ ___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 10 ___________________________________ Physical States of Matter
Matter exists as three physical states: solid, liquid and gas.
___________________________________ A solid has definite shape and volume which
can be independent of its container.
___________________________________ The most common solids are crystalline and have regular,
repeating three-dimensional geometric patterns.
___________________________________ Solid water
molecules are
held together
rigidly and are
very close to each
other.
___________________________________ ___________________________________ ___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 11 ___________________________________ Physical States of Matter
___________________________________ Some solids such as plastics, glass and gels do not have
regular, internal geometric patterns.
___________________________________ These solids are called amorphous solids,
meaning without shape or form.
___________________________________ ___________________________________ ___________________________________ ___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 12 ___________________________________ Physical States of Matter
A liquid has definite volume but not a definite shape.
___________________________________ Liquid particles are held together by strong attractive
forces and are able to move freely.
___________________________________ Liquids are fluid which allows them to take
the shape of the container.
___________________________________ ___________________________________ Liquid water molecules
are close together but
are free to move around
and slide over each other.
___________________________________ ___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 13 ___________________________________ Physical States of Matter
___________________________________ A gas has indefinite volume and no fixed shape.
Gas particles move independently and are relatively far
apart, which allows them to completely fill a container.
___________________________________ Gases can be compressed or expanded almost indefinitely.
___________________________________ ___________________________________ Gaseous water molecules are
far apart and move freely and
randomly.
___________________________________ ___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 14 ___________________________________ Physical States of Matter
___________________________________ Although matter is separated into discrete units,
attractive forces hold the particles together and
give matter its appearance of continuity.
___________________________________ Attractive forces are strongest in solids, giving them
rigidity; weaker in liquids but strong enough to
maintain definite volumes; and weakest in gases
which allows them to behave nearly independently.
___________________________________ ___________________________________ ___________________________________ ___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 15 ___________________________________ Classifying Matter
___________________________________ Matter can be subdivided into specific categories.
___________________________________ A pure substance has a definite, fixed composition
and is either an element or a compound.
___________________________________ The sugar on the spoon and the
water in the beaker are
each a pure substance –
both are compounds.
___________________________________ ___________________________________ ___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 16 ___________________________________ Classifying Matter
___________________________________ Homogeneous matter is uniform in appearance and
has the same properties throughout.
___________________________________ Heterogeneous matter consists of two or more
physically distinct phases.
___________________________________ A phase is a homogeneous part of a system separated
from other parts by a physical boundary.
___________________________________ Ice floating in water is a two phase system.
Each phase is homogeneous but the overall system
is heterogeneous.
© 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 17 ___________________________________ ___________________________________ ___________________________________ Mixtures
A mixture is a combination of two or more
pure substances and can be homo- or heterogeneous.
___________________________________ Sugar dissolved in water is a homogeneous mixture.
The proportion of sugar and water can be varied
but the composition will be the same throughout.
___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide 18 ___________________________________ Mixtures
A heterogeneous mixture will have a different
composition depending on where the sample is taken.
___________________________________ Oil and water form a heterogeneous mixture.
The oil layer floats on top of the water layer.
___________________________________ A sample taken from the top of the mixture will have a
different composition from a sample taken on the bottom.
___________________________________ ___________________________________ ___________________________________ ___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide ___________________________________ Separation of Mixtures
19 ___________________________________ The components of a mixture do not lose their identities
and may be separated by physical means such as:
___________________________________ boiling, filtration, floatation, magnetism
Sulfur and iron can be separated using a magnet.
___________________________________ ___________________________________ ___________________________________ ___________________________________ © 2014 John Wiley & Sons, Inc. All rights reserved.
Slide ___________________________________ Let’s Practice!
20 ___________________________________ ___________________________________ ___________________________________ a.
b.
c.
d.
e.
© 2014 John Wiley & Sons, Inc. All rights reserved.
Slide ___________________________________ Which of the following is a heterogeneous mixture?
baking soda
gasoline
grape juice
copper metal
soil
___________________________________ ___________________________________ ___________________________________ Let’s Practice!
21 ___________________________________ Which of the following is a homogeneous mixture?
a. carbon dioxide
b. mercury
c. maple syrup
___________________________________ d. concrete
e. italian salad dressing
___________________________________ Filtration is a common method to separate components
of what type of mixture?
a.
b.
c.
d.
homogeneous mixture of 2 liquids
heterogeneous mixture of 2 liquids
heterogeneous mixture of solid in liquid
homogeneous mixture of solid in liquid
© 2014 John Wiley & Sons, Inc. All rights reserved.
___________________________________ ___________________________________ ___________________________________