Transcript Introducion to Chemistry - Dr. Vernon-

Introducion to Chemistry
• What is chemistry?
• the study of the properties and
behavior of matter
• physical and chemical properties of
matter
• how different forms of matter change
and interact
• the energy associated with chemical and
physical changes
What is Matter?
• matter is anything that has mass and
takes up space
• over 100 elements are the building
blocks of matter
• an atom is the smallest particle of an
element that retains the properties of
that element
• atoms combine to form compounds,
molecules and formula units
What is Non-Matter?
• Energy!
• Einstein gave us the idea that energy
and matter are related
• E = mc2
Why is it important to study
chemistry?
• Chemistry acts as a sort of backbone
for all of the other sciences.
• Advances in chemistry contribute to:
virtually every aspect of our everyday
lives, including, but not limited to:
Why is it important to study
chemistry?
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the development of new medicines
conservation of natural resources
clean-up of the environment
food production
nutrition
manufacture of goods….EVERYTHING
Scientific World View
• Some tenets of the scientific world
view include:
• the world is understandable
• scientific ideas are subject to change
• scientific knowledge is durable
• science cannot provide complete
answers to all questions
Scientific Inquiry
• All science demands evidence, but scientists differ in
the type of evidence they rely on and how they go
about answering questions.
• qualitative observations vs. quantitative
measurements
• natural settings vs. controlled
laboratory experiments
• passive vs. active
• Despite differences in technique and approach, there
is general agreement about what constitutes an
investigation that is scientifically valid.
Scientific Inquiry
Process Skills
1. Questioning
– Formulating Questions
– Defining Problem Statements
– Recognizing limits to the investigation
2. Proposing Ideas
– Hypothesizing (Predictions)
– Use background information
Scientific Inquiry
Process Skills
3. Designing Experiments
– Controlling variables
– Determining Procedures
– Evaluate experimental design
4. Gathering data
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Observing
Measuring
Making data tables
Recording data
Scientific Inquiry
Process Skills
5. Processing data
– Organizing and presenting data
– Manipulating data (calculating or
graphing)
– Determining experimental error
• % error or
• % yield
Scientific Inquiry
Process Skills
6. Interpreting Data
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Determine if your hypothesis was
supported or not
Generating explanations, theories and
models
Determine patterns or trends
Identifying the limits to the
interpretation
Generating further ideas for
experimentation
Questioning
Proposing ideas
Designing experiments
Gathering data
Processing data
Interpreting data
Experimental Design
• Laboratories allow scientists to control
their experiments so observations are
reproducible.
• EXAMPLE: Francisco Redi’s Maggot
Farm-1600s
Francisco Redi’s Maggot Farm—
17th Century
• In the 1600’s it was widely believed
that living things could arise
spontaneously from non-living, dead,
or waste materials (this is called
spontaneous generation), because
people saw such materials "generate"
living things such as mold or
maggots.
Francisco Redi’s Maggot Farm—
17th Century
• In 1688, Italian naturalist Francisco
Redi set out to test the idea with
decaying meat in two containers: one
open to the air, the other
sealed. The open container meat
eventually became infested with
maggots.
Francisco Redi’s Maggot Farm—
17th Century
Francisco Redi’s Maggot Farm—
17th Century
• And when critics insisted that it was
the sealing of the second container
that kept spontaneous generation from
occurring, Redi did the test with an
open container and one covered with
cheesecloth, through which air could
circulate, and the cheeseclothcovered sample produced no maggots.
Francisco Redi’s Maggot Farm—
17th Century
Source: http://faculty.fmcc.suny.edu/mcdarby/Animals&PlantsBook/History/03-Explaining-Life-Science.htm
Variables- Good experiments are
controlled.
• 1. Manipulated variable (independent
variable) –
• Redi’s experiment –
Variables- Good experiments are
controlled.
• 2. Responding variable (dependent
variable)• Redi’s experiment-
Variables- Good experiments are
controlled.
• 3. Controlled variables (constants)• Redi’s Experiment-
Problem statement: What is the
effect of increasing the
frequency of teeth brushing on
the amount of plaque build-up?
• MV:
• RV:
• CV’s:
Metrics and Measurement
• Shift to the Student notes for
• “METRICS AND MEASUREMENT”