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CHAPTER 1

CHAPTER 1. Introduction to Chemistry. Vocabulary/Study Guide. Define each term using the Glossary Either write on the handout, or use your own paper This is due on Test Day (tentatively, Tuesday, August 27). Section 1: A Story of Two Substances. National Standards:

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CHAPTER 1

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  1. CHAPTER 1 Introduction to Chemistry

  2. Vocabulary/Study Guide • Define each term using the Glossary • Either write on the handout, or use your own paper • This is due on Test Day (tentatively, Tuesday, August 27)

  3. Section 1: A Story of Two Substances • National Standards: • UCP.1 Systems, order, and organization • UCP.2 Evidence, models, and explanation • A.1 Abilities necessary to do scientific inquiry • A.2 Understandings about scientific inquiry • B.3 Chemical reactions • B.6 Interactions of energy and matter • E.2 Understandings about science and technology • F.4 Environmental quality • F.5 Natural and human-induced hazards • G.2 Nature of scientific knowledge • G.3 Historical perspectives

  4. Essential Questions • What is a substance? • How does ozone form and why is it important? • What are chlorofluorocarbons and how do they get into the atmosphere?

  5. Why Study Chemistry? • All the stuff in the universe is made from building blocks formed in stars • These building blocks are called matter – anything that has mass and takes up space • Chemistry is the study of matter and the changes that it undergoes

  6. The Ozone Layer • Overexposure to ultraviolet radiation is harmful to both plants and animals • Increased levels of UVB can cause cataracts, skin cancer, lower crop yields in agriculture, and disrupted food chains in nature • Ozone (O₃) is a substance in the atmosphere that absorbs most harmful UV radiation before it reaches Earth’s surface • substance: matter that has a definite composition; also known as a chemical

  7. The ozone layer that protects Earth is located in the stratosphere, that layer of Earth’s atmosphere just above the troposphere (where we live)

  8. Ozone forms over the equator, where the rays of sunlight are the strongest, and then flows toward the poles.

  9. Between 1981 and 1983, a research group from the British Antarctic Survey measured surprising low l levels of ozone, especially during the Antarctic spring in October.

  10. Chlorofluorocarbons • In the 1920’s, large-scale production of refrigerators began, which used ammonia as coolant. • In an attempt to find safer coolant, chemist, Thomas Midgley, Jr. synthesized the first chlorofluorocarbons in 1928.

  11. CFC’s (con’t) • A Chlorofluorocarbon (CFC) is a substance that consists of chlorine, fluorine and carbon. • All substances that are classified as CFCs are: • Man-made (they do not occur naturally) • Nontoxic • Stable (they do not readily react with other substances) • Because of being nontoxic and very stable, they seemed to be ideal coolants for refrigerators and AC units, for use in plastic foams and as propellants in spray cans.

  12. CFCs were first detected in the atmosphere in the 1970s, and the concentrations continued to increase through the 1990s. • Could there be a connection between ozone thinning and increasing CFCs in the atmosphere?

  13. Homework • SECTION 1 REVIEW, Page 8 • Questions #1, 3, 4, 5, 6, 7 • Answer with complete sentences • Due tomorrow

  14. Section 2: Chemistry and Matter • National Standards: • UCP.1 Systems, order, and organization • UCP.2 Evidence, models, and explanation • A.1 Abilities necessary to do scientific inquiry • B.2 Structure and properties of matter • G.1 Science as a human endeavor • G.2 Nature of scientific knowledge

  15. Essential Questions • How do mass and weight compare and contrast? • Why are chemists interested in a submicroscopic description of matter? • What defines the various branches of chemistry?

  16. Matter and its Characteristics • Matter is anything that has mass and takes up space • Mass is a measure that reflects the amount of matter • Is air matter? {DEMOS} • Matter has mass (balloon, scale) • Matter takes up space (beaker with water, paper cup, tissue, scissors)

  17. Matter and its Characteristics • Weight is a measure of the effect of Earth’s gravitational pull on matter • This varies from place to place on Earth, and from planet to planet • Scientists use mass for measurements so they can compare the measurements that they make in different parts of the world

  18. MASS vs. WEIGHT MASS WEIGHT Measures the pull/force of gravity Varies from place to place The units are ounces and pounds • Measures the amount of matter • Is constant • The units are grams and kilograms

  19. Matter and its Characteristics • Much of matter and its behavior is macroscopic • Matter can be broken down into more than a hundred types of matter called elements • Elements are made up of particles called atoms • The structure, composition, and behavior of all matter can be explained on a submicroscopic level • Also called the atomic level • All that we observe about matter depends on atoms and the changes they undergo

  20. Matter and its Characteristics • Chemistry explains events on the atomic level (submicroscopic) that cause macroscopic observations. • A model is a verbal, visual, or mathematical explanation of experimental data.

  21. Chemistry: The Central ScienceChemistry is traditionally broken into branches that focus on specific areas such as:

  22. Homework • SECTION 2 REVIEW, Page 11 • Questions #8, 9, 12, 13 • Answer with complete sentences • Due tomorrow

  23. Section 3: Scientific Methods • National Standards: • UCP.1 Systems, order, and organization • UCP.2 Evidence, models, and explanation • A.2 Understandings about scientific inquiry • G.1 Science as a human endeavor • G.2 Nature of scientific knowledge

  24. Essential Questions • What are the common steps of scientific methods? • What are the similarities and differences between qualitative data and quantitative data? • In an experiment, which variable is the independent variable, which is the dependent variable, and which are controls? • What is the difference between a theory and a scientific law?

  25. A Systematic Approach • It is helpful if all scientists use common procedures as they conduct their experiments • A scientific method is a systematic approach used in scientific study • This is an organized process used by scientists to do research, and • It provides a method for scientists to verify the work of others • If other scientists cannot confirm the results after repeating the methods, then doubt arises over the validity of the results

  26. Scientific Methods SECTION1.3 A Systematic Approach (cont.) The steps in a scientific method are repeated until a hypothesis is supported or discarded.

  27. A Systematic Approach Qualitative Data Quantitative Data Numerical information such as temperature, pressure, volume, the quantity of a chemical formed, or how much of a chemical is used up in a reaction Tells how much, how little, how big, how tall, or how fast People’s scores on tests would be quantitative data • Uses the five senses – how something looks, feels, sounds, tastes, or smells • Information that describes color, odor, shape, or some other physical characteristic • People’s responses on surveys would be a type of qualitative data

  28. A Systematic Approach • An experiment is a set of controlled observations that test the hypothesis • A variable is a quantity or condition that can have more than one value • An independent variableis the variable you plan to change. • The dependent variableis the variable that changes in value in response to a change in the independent variable. • A control is a standard for comparison

  29. A Systematic Approach • Writing a Lab Report includes: • Title • Objective or Hypotheses • Prediction • Data • Analysis • Conclusion

  30. Mini-Lab: Develop Observation Skills TITLE: DEVELOP OBSERVATION SKILLS OBJECTIVE: Students need to understand the importance of observation skills in Chemistry because observations are often used to make inferences. PREDICTION: Define inference. How will dishwashing detergent affect vegetable oil? How will dishwashing detergent affect whole milk?

  31. Scientific Methods SECTION1.3 A Systematic Approach (cont.) Molina and Rowland’s model showed how CFCs could destroy ozone.

  32. Theory and Scientific Law Theory Scientific Law A relationship in nature that is supported by many experiments Many scientists come to the same conclusion about certain relationships in nature and they find no exceptions to these relationships Scientists develop further hypotheses and experiments to explain why these relationships exist • An explanation of a natural phenomenon based on many observations and investigations over time • States a broad principle of nature that has been supported over time • Still subject to new experimental data and can be modified • A theory is considered valid if it can be used to make predictions that are proven true

  33. Homework • SECTION 3 REVIEW, Page 16 • Questions #17, 18, 19 • Answer with complete sentences • Due tomorrow

  34. Section 4: Scientific Research • National Standards: • UCP.1 Systems, order, and organization • UCP.2 Evidence, models, and explanation • A.1 Abilities necessary to do scientific inquiry • A.2 Understandings about scientific inquiry • B.2 Structure and properties of matter • B.6 Interactions of energy and matter • E.2 Understandings about science and technology • F.1 Personal and community health • F.4 Environmental quality • F.6 Science and technology in local, national, and global challenges • G.1 Science as a human endeavor • G.2 Nature of scientific knowledge • G.3 Historical perspectives

  35. Essential Questions • How do pure research, applied research, and technology compare and contrast? • What are some of the important rules for laboratory safety?

  36. Types of Scientific Investigations • Pure research is research to gain knowledge for the sake of knowledge itself. • Applied researchis research undertaken to solve a specific problem. • Chance discoveries occur when scientists obtain results that are far different from what they expected. • Ex. Alexander Fleming’s discovery of Penicillin.

  37. Students in the Laboratory • You are responsible for your safety and the safety of others around you. • Refer to Table 1.2 on page 19 of your textbook for a list of safety rules in the laboratory.

  38. The Story Continues • Applied research showed that CFCs and a few other chemicals react with ozone. • Many nations agreed in 1987 to the Montreal Protocol, to phase out CFC use.

  39. Data Analysis Lab: Interpret Graphs Title: Interpret Graphs (page 21) Objective: To determine how ozone levels vary throughout the year. Think Critically: • 1. Describe the trend in the data for 1979-2008. • 2. Evaluate how the 2009 data compare with the data from 1979-2008. • 3. Identify the month during which the ozone levels were the lowest in 1979-2008. In 2009? • 4. Assess – Do these data points back up what you learned in this chapter about ozone depletion? Explain your answer.

  40. The Benefits of Chemistry • Chemists solve many real problems we face today such as: • Ozone depletion • Finding cures for diseases • Reducing automobile pollution

  41. Homework • SECTION 4 REVIEW, Page 22 • Questions #20, 23, 24 • Answer with complete sentences • Due tomorrow

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