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Describe how Lavoisier transformed
chemistry
Identify the steps in the scientific method
Explain why collaboration and
communication are important in science
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Scientific method
Observation
Hypothesis
Experiment
Manipulated variable
Responding variable
Theory
Scientific law
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Alchemy: was the study of matter that came
before chemistry
It rose from many different regions of the
ancient world and was practiced as early as 400
B.C.
It had two sides: practical & mystical
Practical alchemy focused on developing
techniques for working with metals, glass, &
dyes
Mystical alchemy focused on concepts like
turning lead into gold
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Ultimately, alchemists developed the
tools and techniques for working with
chemicals
Alchemists developed processes for
separating mixtures and purifying chemicals
They designed equipment such as: beakers,
flasks, tongs, funnels, and the mortar &
pestle
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By the 1500’s alchemy was a thing of the past
and science flourished
In the 1600’s, the Royal Society of London for
the Promotion of Natural Knowledge, the first
scientific organization, was formed
They met to discuss scientific topics and
conduct experiments
The society’s aim was to encourage scientists
to base their conclusions about the natural
world on experimental evidence
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Famous chemist of the 1700’s in
France
He helped to transform chemistry
from a science of observation to a
science of measurement
As brilliant as he
He designed a balance to measure was, it did not save
from the
mass to the nearest 0.005 gram him
revolutionary
He also through experimentation guillotine
proved how things burn
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Is a logical systematic approach to the
solution of a scientific problem
Steps in the scientific method:
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Making observations
Forming a hypothesis
Testing a hypothesis
Drawing conclusions
Communicating results
They Might be Giants: Scientific Method
Song
 Monty Python demos the scientific method
 Big Bang Theory: Scientific Method
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Requires using your senses to obtain
information
This information can then lead to a question
to be answered
For example, while on vacation in Alaska
you observed the aurora borealis
This leads you to ask “What causes the
different colors of light?”
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Using our previous example, we proposed that
the different colors of light are due to different
gases.
Coming up with a possible explanation for an
observation is called a hypothesis
The procedure for testing a hypothesis is called
an experiment
When we design an experiment, we have to
deal with variables, or factors that change
What could we do for an experiment to test
our hypothesis?
Manipulated
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Is the variable you
change in an
experiment
Also called the
independent
variable
What would our
manipulated
variable be?
Responding
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Is the variable you
observe during the
experiment
Also called the
dependent variable
What would our
responding variable
be?
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Once a hypothesis meets the test of repeated
experimentation, it may become a theory
A theory is a well tested explanation for a
broad set of observations
For example: chemistry’s focus is the
fundamental structure of matter theory
Theories allow us to predict the behavior of
matter or visualize processes that we can not
see
Theories can change and can be disproved
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A scientific law is a concise statement
that summarizes the results of many
observations and experiments
For example: we will discuss the gas laws
A law doesn’t try to explain the relationship
it describes
A theory is required for an explanation
Collaboration
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Is the joining of
scientists, usually from
different areas of
expertise to solve a
problem
It is a practical choice
since no one is an expert
in everything
However, it isn’t always
a smooth process
Communication
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Is essential for sharing
scientific ideas with
other scientists as well
as the public
The methods have
changed with the
development of
technology
However, scientist still
publish their work in
scientific journals