Introduction to Chemistry
Section 1:
Section 2:
Section 3:
Section 4:
A Story of Two Substances
Chemistry and Matter
Scientific Methods
Scientific Research
• Section 1: Chemistry is the study of everything around
us.
• Section 2: Branches of chemistry involve the study of
different kinds of matter.
• Section 3: Scientists use scientific methods to
systematically pose and test solutions to questions and
assess the results of the tests.
• Section 4: Some scientific investigations result in the
development of technology that can improve our lives
and the world around us.
Vocabulary
Review
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matter
technology
systematic approach
synthetic
New
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chemistry
substance
mass
weight
model
scientific method
qualitative data
New continued
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quantitative data
hypothesis
experiment
independent variable
dependent variable
control
conclusion
theory
scientific law
pure research
applied research
A Story of Two Substances
Section 1
Section 1: A Story of Two Substances
• Chemistry is the study of everything around us.
K
What I Know
W
What I Want to Find Out
L
What I Learned
Why Study Chemistry?
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All the “stuff” in the universe is made from building blocks formed in stars.
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These building blocks and everything made from them are called matter.
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Chemistry is the study of matter and the changes it undergoes.
What is Chemistry?
The Ozone Layer
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Ultraviolet radiation damages living organisms.
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Earth’s atmosphere contains a layer of ozone that absorbs most ultraviolet
radiation and protects living organisms.
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Ozone is a substance in the atmosphere made up of oxygen.
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A substance, also known as a chemical, is matter that has a definite
composition.
The Ozone Layer
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Earth’s atmosphere consists of several layers. The protective ozone layer is
located in the stratosphere.
The Ozone Layer
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Ozone, in the stratosphere, is formed when oxygen gas (O2) is exposed to
ultraviolet radiation.
The Ozone Layer
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Ozone has interested and been studied by scientists since the late 1800’s.
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Ozone forms over the equator, where the rays of sunlight are the strongest
and then flows towards the poles, thus, making it a convenient marker to
follow the flow of air in the stratosphere.
The Ozone Layer
The Ozone Layer
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In the mid-1980s, Scientists detected thin areas in the ozone layer over
Antarctica.
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What could be causing the ozone hole?
Chlorofluorocarbons
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In the 1920’s, large-scale production of refrigerators began, which used ammonia as coolant.
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In an attempt to find safer coolant, chemist, Thomas Midgley, Jr. synthesized the first
chlorofluorocarbons in 1928.
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A Chlorofluorocarbon (CFC) is a substance that consists of chlorine, fluorine and carbon.
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All substances that are classified as CFCs are:
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Man-made (they do not occur naturally)
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Nontoxic
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Stable (they do not readily react with other substances)
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Because of being nontoxic and very stable, they seemed to be ideal coolants for refrigerators
and AC units, for use in plastic foams and as propellants in spray cans.
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CFCs
Chlorofluorocarbons
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CFCs were first detected in the
atmosphere in the 1970s, and the
concentrations continued to increase
through the 1990s.
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Could there be a connection between
ozone thinning and increasing CFCs in
the atmosphere?
Review
Essential Questions
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What is a substance?
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How does ozone form and why is it important?
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What are chlorofluorocarbons and how do they get into the atmosphere?
Vocabulary
• chemistry
• substance
Chemistry and Matter
Section 2
Section 2: Chemistry and Matter
• Branches of chemistry involve the study of different kinds of matter.
K
What I Know
W
What I Want to Find Out
L
What I Learned
Matter and its characteristics
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Matter is anything that has mass and takes up space.
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Mass is a measurement that reflects the amount of matter.
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Weight is a measure of mass and force of gravity on an object. Weight can
change from place to place, but mass is constant.
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Much of matter and its behavior is macroscopic, meaning that it can be observed
without a microscope.
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The structure, composition, and behavior of all matter can be described on the
submicroscopic (atomic) level.
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Chemistry explains events on the atomic level that cause macroscopic
observations.
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A model is a verbal, visual, or mathematical explanation of experimental data.
Weight VS Mass
Chemistry: The Central Science
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A basic understanding of chemistry is central to all sciences – biology,
physics, Earth science, ecology, etc. Chemistry is traditionally broken into
branches that focus on specific areas such as:
– Organic chemistry
– Inorganic chemistry
– Physical chemistry
– Analytical chemistry
– Biochemistry
– Environmental chemistry
– Industrial chemistry
– Polymer chemistry
– Theoretical chemistry
– thermochemistry
Match what you think is the branch of chemistry to
its area of emphasis (start with what you do know)
Branch
• Analytical chemistry
• Industrial chemistry
• Physical chemistry
• Biochemistry
• Inorganic chemistry
• Polymer chemistry
• Thermochemistry
Area of Emphasis
• Most carbon-containing
chemicals
• In general, matter that doesn’t
contain carbon
• The behavior and changes of
matter and the related energy
changes
• Components and composition of
substances
• Matter and processes of living
organisms
• Matter and the environment
• Chemical processes in industry
• Polymers and plastics
• Chemical interactions
• Heat involved in chemical
processes
Review
Essential Questions
• How do mass and weight compare and contrast?
• Why are chemists interested in a submicroscopic description of
matter?
• What defines the various branches of chemistry?
Vocabulary
• Mass
• weight
• model
Scientific Methods &
Research
Section 3 & Section 4
Section 3 & 4: Scientific Methods & Research
• Scientists use scientific methods to systematically pose and test
solutions to questions and assess the results of the tests.
• Some scientific investigations result in the development of
technology that can improve our lives and the world around us.
K
What I Know
W
What I Want to Find Out
L
What I Learned
A Systematic Approach
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The scientific method is a systematic approach used in scientific study,
whether it is chemistry, physics, biology, or another science.
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It is an organized process used by scientists to do research, and provides
methods for scientists to verify the work of others.
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The steps in a scientific method are repeated until a hypothesis is supported
or discarded.
A Systematic Approach
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An observation is the act of gathering information.
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Qualitative data is obtained through observations that describe color, smell, shape, or some
other physical characteristic that is related to the 5 senses.
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Quantitative data is obtained from numerical observations that describe how much, how little,
how big, or how fast.
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A hypothesis is a tentative explanation for what has been observed.
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An experiment is a set of controlled observations that test the hypothesis.
A Systematic Approach
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A variable is a quantity or condition that can have more than one value.
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An independent variable is the variable you plan to change.
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The dependent variable is the variable that changes in value in response to a change in the
independent variable
EXAMPLE: If you were trying to determine if temperature affects bacterial
growth, you would expose different petri dishes of the same bacteria to
different temperatures
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Temperature is your independent variable
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Bacteria growth is your dependent variable
Variables Song (Creepy guy)
A Systematic Approach
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A control is a standard for comparison in the experiment.
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During clinical drug trials, physicians will use a double-blind study. They use 2
statistically identical groups of patients. 1 will receive the drug and 1 will
receive a placebo (sugar pill). Neither patient or physician know which group
receives the drugs.
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The group receiving the placebo is the control group.
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A conclusion is a judgment based on the information obtained from the
experiment.
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A hypothesis is never proven, only supported or discarded.
Experiments
Theory and Scientific Law
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A theory is an explanation that has been repeatedly supported by many
experiments.
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A theory states a broad principle of nature that has been supported over time by repeated
testing.
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Theories are successful if they can be used to make predictions that are true.
A scientific law is a relationship in nature that is supported by many
experiments, and no exceptions to these relations are found.
Types of Scientific Investigations
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Pure research is research to gain knowledge for the sake of knowledge itself.
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Applied Research is research undertaken to solve a specific problem.
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Change discoveries occurs when scientists obtain results that are far different
from what they expected.
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Sometimes accidents are better! Alexander Fleming’s discovery of Penicillin has saved millions.
Accidental Discoveries
Review
Essential Questions
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What are the common steps of scientific method?
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What are the similarities and differences between qualitative data and quantitative
data?
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In an experiment, which variable is the independent variable, which is the dependent
variable, and which are controls?
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What is the difference between a scientific theory and a scientific law?
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How do pure research, applied research, and technology compare and contrast?
Vocabulary
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Scientific method •
Qualitative data
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Quantitative data •
Hypothesis
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Experiment
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Independent variable
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Dependent variable•
Control
Conclusion
Theory
Scientific law
Synthetic
Pure research
Applied research