Chapter 1 “Chemistry and You”

1. Chapter 1 “Chemistry and You” Or “Why should I take Chemistry?”

2. “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.

3. 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?

4. 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.

5. 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.

6. 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!

7. Is Chemistry Hard? • NO! • It’s like learning a new language through which we are able to understand the sub-microscopic world.

8. 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.

9. 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!

10. 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.

11. 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)

12. 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.

13. The Scientific Method: 1. OBSERVATION 2. QUESTION 3. HYPOTHESIS 4. EXPERIMENT 5. CONCLUSION THEORY NATURAL LAW MODIFY THEORY AS NEEDED PREDICTION EXPERIMENT

14. 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.

16. 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?

17. 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.

18. 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.

19. 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.

20. 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.