Measurements in Chemistry Worksheets

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					Chapter 1 “Chemistry and
          You”
               Or
 “Why should I take Chemistry?”
“Why should I take Chemistry?”
• Here are some good reasons:
  – Impress your family and friends by using words like
    “stoichiometry,” “colligative properties,” “anions,”
    “cations” and “redox.”
  – “Chemistry” will look good on your transcript.
  – You will finally learn what goes into hotdogs.
  – Discover the difference between “moles,” “moles,”
    and “moles.”
  – Find out how fireworks color the sky.
  – Learn how to calculate the volume of 637 grams of
    steam at 2,000°C and 5 atmospheres of pressure.
    QUESTIONS FOR THE FIRST DAY
       OF CHEMISTRY CLASS
•   What is Chemistry?
•   How does Chemistry impact us in our
    daily life?
•   What human activities require Chemistry?
•   Why is Chemistry considered the „central‟
    science?
•   Is Chemistry hard?
•   How can I get an “A” in this class?
          Chapt. 1 Objectives
• Explain what chemistry is, and why it is important to
  many human activities.
• List and describe the steps of the Scientific Method.
• Explain the basic safety rules to be followed when
  working in the laboratory.
• Identify the metric units of measurement.
• Explain the causes of uncertainty in measurements.
• Compare “precision” and “accuracy.”
• Explain the use of significant figures and scientific
  notation.
• Calculate percent error, and determine density.
• Explain how dimensional analysis and conversion factors
  are used in solving problems in chemistry.
      1-1 What is Chemistry?


• Chemistry is the study of substances and the
  changes they can undergo.

• Chemistry is the ‘central science’ because it
  overlaps and impacts so many other sciences.

• Do Now: Use these two concepts to show how
  chemistry is used by people you know.
         Why study Chemistry?
• It affects our lives in many ways.
   – Food, medicine, biotechnology, fuels, transportation, electronics,
     plastics, the environment, clothing, etc. involve chemicals.
   – Everything we wear, eat, drink and use is chemical.
   – In fact, we, too, are made up of chemicals (mostly water!).
• It helps us understand things around us.
   – Like rusting cars, cooking food, coloring our hair, floating
     balloons, treating diseases, making electronics.
   – We will be able to arrive at informed opinions and take suitable
     action on issues.
• It could lead to an interesting career.
   – Art historian, research scientist, environmentalist, materials
     scientist, physician, technical writer, patent lawyer and hundreds
     of other occupations requiring some knowledge of chemistry.
• Besides, Chemistry is fun!
          Is Chemistry Hard?




• NO!
• It‟s like learning a new language through which
  we are able to understand the sub-microscopic
  world.
 What skills will I develop by studying
              Chemistry?
• Technical reading skills (which differ from
  „casual‟ reading skills).
• Good observation skills.
• Organizational, analytical and interpretive
  skills (the „thinking‟ skills).
• Good factual recall.
• Mathematical manipulations, especially
  from text problems and graphs.
• Valuable laboratory skills.
        Tips for Studying Chemistry
              (Getting that ‘A’!)
• Make an effort every day!
• Read the topics more than once, & write notes to
  summarize what you read.
• Use the slides and outlines provided on-line.
• Try to explain the concepts to someone else.
• Use the text, including the drawings & photos.
• Get organized, and stay that way.
• Solve lots of practice problems, and complete all
  of the worksheets and assignments.
• Work alone or in groups.
• Get help when you need it!
           Chapt. 1 Objectives
• Explain what chemistry is, and why it is important to
  many human activities.
• List and describe the steps of the Scientific Method.
• Explain the basic safety rules to be followed when
  working in the laboratory.
• Identify the metric units of measurement.
• Explain the cause of uncertainty in measurements.
• Compare precision and accuracy.
• Explain the use of significant figures and scientific
  notation.
• Calculate percent error, and determine density.
• Explain how dimensional analysis and conversion factors
  are used in solving problems in chemistry.
     1-2 The Scientific Method
• The Scientific Method is a way of answering
  questions about the world around us.

• It is an orderly and systematic approach to gather
  knowledge, develop ideas, check those ideas against
  observations, and to refine the ideas.

• Chemistry makes use of the cycle:
                        OBSERVE




            INTERPRET             HYPOTHESIZE (Represent)
  Steps of the Scientific Method
• Make an observation.
• Pose a question about the observation.
• Propose a hypothesis to tentatively answer the
  question.
• Test the hypothesis with careful experiments.
• Interpret the experiments and generate a conclusion.
• Since the experiments may lead to new questions,
  additional experiments may be needed and the
  conclusions may need to be revised.
• Pose a natural law, which describes how (but not why)
  nature behaves the way it does.
• Formulate a theory to explain why nature behaves in the
  way it does.
 The Scientific Method:       1. OBSERVATION
                              2. QUESTION
                              3. HYPOTHESIS
                              4. EXPERIMENT
                              5. CONCLUSION




                   THEORY
                                               NATURAL
                                                 LAW
MODIFY THEORY
 AS NEEDED       PREDICTION


                EXPERIMENT
                 Activities
• Since good observation skills are at the
  start of the Scientific Method, let’s test
  your skills.
  – View the next slide and record your
    observations.
  – Pose a question about what you see.
  – Try to organize the information, and propose
    a hypothesis to explain it.
  – Suggest an experiment to test the hypothesis.
     Hypothesis & Experiment
• Practice Problems (pages 10, 11).

• Experiment
  – Variables: the factors being tested.
  – Controls: factors that respond in a predictable way.

• Many experiments lead to
  – Natural Laws (These summarize many observations,
    but the Natural Law does not explain things.)
  – Theory (This provides the explanation, or a “super
    hypothesis.”)
  – Is this the end of the story?
                        NO!
• Even long-accepted scientific theories may be
  revised (or even abandoned) as new scientific
  evidence emerges from carefully run
  experiments.
  – The “Flat Earth Society.”
  – The Earth as the center of the Universe!
  – Pluto as a planet.


• We will see how this works when we study the
  development of the Atomic Theory.
                   Objectives
• Explain what chemistry is, and why it is important to
  many human activities.
• List and describe the steps of the Scientific Method.
• Explain the basic safety rules to be followed when
  working in the laboratory.
• Identify the metric units of measurement.
• Explain the cause of uncertainty in measurements.
• Compare precision and accuracy.
• Explain the use of significant figures and scientific
  notation.
• Calculate percent error, and determine density.
• Explain how dimensional analysis and conversion factors
  are used in solving problems in chemistry.
  1-3 Safety in the Laboratory
• Demonstrations
  – Prof. Ira Remsen‟s experiment.
  – “The Egg and the Eye.”
  – Contact lenses.
  – Fire! Fire!
  – Scavenger hunt.
  – Safety symbols (page 15).
  – Safety Rules.
  – Safety Contract.
  Did We Meet the Objectives?
• Explain what chemistry is, and why it is important to
  many human activities.
• List and describe the steps of the Scientific Method.
• Explain the basic safety rules to be followed when
  working in the laboratory.
• Identify the metric units of measurement.
• Explain the cause of uncertainty in measurements.
• Compare precision and accuracy.
• Explain the use of significant figures and scientific
  notation.
• Calculate percent error, and determine density.
• Explain how dimensional analysis and conversion factors
  are used in solving problems in chemistry.

				
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