Unit 1 Science Skills

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Unit 1Science Skills

• Mrs. Johnston

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What will we learn about?

• Science is observing, studying, and experimenting
  to find the nature of things. Natural Science
  attempts to understand the whole universe.
  Natural Science consists of life science,
  physical science, and earth science. Physical
  Science breaks down into chemistry and physics.
  Chemistry is the study of matter and its changes.
  Physics is the study of forces and energy.

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What is physical science?

• Everything in the universe that can be measured
  in some way is either MATTER or ENERGY.
• All matter has energy that changes as the matter
  changes.
• The study of physical science is the study of
  matter and its composition and how it behaves.

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What will we do this year?

• Learn about physics and chemistry.
• Do lots of cool experiments.
• Be safe.
• Have fun.

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First the paperwork!

• Read the safety contract with one of your
  parents!
• Sign and return
• Take the lab safety test.
• Pass

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Whats Wrong in the Lab?
Mark, Jenn, Juan, and Tina were eager to begin
testing the properties of elements. Jenn lit the
Bunsen burner, then reached across the flame to
hand a test tube to Juan. Juan placed a sample
of element A in the test tube and began to heat
it. Every so often she would peer into the test
tube to see what was happening. Meanwhile, Mark
was looking at a sample of liquid element B. It
seemed to have an unusual odor, so he took a deep
whiff of it. Then he put a drop of it on his
finger to taste. By this time, Juan was tired of
heating element A, so he decided to heat a sample
of element C even though the instructions in the
textbook stated that only element A was to be
heated. As Juan tried his experiment, Tina began
to observe the properties of element D by
reacting it with acid, As she placed acid on the
sample, she splashed some on her hand, then
splashed a little more on the sleeve of her
shirt. Then, leaving the top off the bottle of
acid, she went on to test something else. When
the group was finished working, they left the
element samples and chemicals on the test tubes
and put them away. One of the test tubes had a
crack in it, but since it was not very large,
they put the test tube away with the others. As
she was leaving the lab, Tina noticed that she
had a small cut on her finger. She decided that
it was not important and did not mention it to
anyone.
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What makes a safe lab?

• Try to answerthese questions!Look at the
  safety contract for help.

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Scientific Method

• The scientific method is a way to ask and answer
  scientific questions by making observations and
  doing experiments.
• The steps of the scientific method are to
• Ask a Question
• Do Background Research
• Construct a Hypothesis
• Test Your Hypothesis by Doing an Experiment
• Analyze Your Data and Draw a Conclusion
• Communicate Your ResultsIt is important for
  your experiment to be a fair test. A "fair test"
  occurs when you change only one factor (variable)
  and keep all other conditions the same.
  Explanation of the scientific method.

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What is an Experiment?

• Scientist experiment by testing a hypothesis.
• In many experiments a control is needed. It
  validates or proves your findings. It is what
  you compare your results to to prove your
  hypothesis.
• A constant in an experiment is one that does not
  change in the experiment.
• Independent variable is the factor adjusted by
  the experimenter.
• A dependent variables value is dependent on the
  independent variables value.

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Scientific Method
If you still dont understand scientific method
here are some places to look. Ask me if you
still dont get it. If you understand, HOORAY!

• Here is an explanation of the scientific method.
  Its for middle school but is very good.
• This explanation is a little longer but
  interesting.

Ask your teacher
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Lab Instruments
Do you know what these lab instruments are?

• Article explains in detail how to use different
  science lab instruments.

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Measurement in Science

• Science uses the SI standard of measurements.
• SI is accepted worldwide.
• Want to know more?
• Even more.
• See if you understand it.

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Measurement in Science

• The SI system is easy to use because it is based
  on powers of ten. (Metric)
• For example the prefix Kilo means 1000, so a
  kilometer is 1000 meters.
• Quick quiz to check understanding.
• Try these conversions.

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The Metric System

• Clear explanation on how to use the metric
  system.
• Conversion information
• Explanation of metric conversion
• Liters and milliliters

Ask your teacher
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Scientific Notation

• Scientific notation is a way to show where the
  decimal point is in a measurement or value.
• Positive number moves right
• 104 means move right 4 times
• 5.4 x 104 54,000
• Negative number moves left
• 10-4 means move left 4 times
• 5.4 x 10-4 0.00054

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Significant Digits

• Digits from 1-9 are always significant.
• Zeros between two other significant digits are
  always significant
• One or more additional zeros to the right of both
  the decimal place and another significant digit
  are significant.
• Zeros used solely for spacing the decimal point
  (placeholders) are not significant.

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Significant Figures

• Practice
• Why are they important?
• More information than you need but interesting.

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Precision vs. Accuracy

• The dictionary definitions of these two words do
  not clearly make the distinction as it is used in
  the science of measurement.
• Accurate means "capable of providing a correct
  reading or measurement." In physical science it
  means 'correct'. A measurement is accurate if it
  correctly reflects the size of the thing being
  measured.
• Precise means "exact, as in performance,
  execution, or amount. "In physical science it
  means "repeatable, reliable, getting the same
  measurement each time."
• We can never make a perfect measurement. The best
  we can do is to come as close as possible within
  the limitations of the measuring instruments.

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Precision vs. Accuracy

• Let's use a model to demonstrate the difference.
• Web site that demonstrates precision vs.
  accuracy.
• Check your understanding.

High accuracy low precision
Low accuracy high precision
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Graphing

• A graph is a visual display of information or
  data. There are three types of graphs, line
  graph, bar graph, and circle graph.

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Line Graph

• Line graphs are used to show trends or how data
  changes over time.
• In a line graph the dependent variable is plotted
  on the y-axis (vertical) and the independent
  variable is plotted on the x-axis (horizontal).
• Example In a line graph to show temp change in a
  room over time- independent variable is time and
  is on the x-axis and the dependent variable would
  be temp and is on the y-axis.

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Bar Graph

• A bar graph is useful for comparing information
  collected by counting.
• You would not have an independent or dependent
  variable to consider.
• Example Comparing temps in different rooms- Bar
  would be the room on the y-axis and the x-axis
  would be the temperature of room.

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Circle graphs

• A circle or pie graph is used to show how a fixed
  quantity is broken down into parts.
• The whole pie represents the quantity. Each
  slice represents parts and are notated in
  percentages.
• Example A pie graph of your budget- the circle
  is all your money and the slices show how you
  spend it.

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Graphs

• More information
• Graph paper
• Graphing practice

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Review

• Metric, Lab, Scientific Method
• Labs and the Scientific Method