1. 1.2 Chemistry and You > 1 chemistry Branches of Chemistry

2. 1.2 Chemistry and You > 2 Learning Target: I can describe what is studied in chemistry & 5 branches of chemistry I can describe the big ideas in chemistry I can describe 3 reasons to study chemistry

3. 1.2 Chemistry and You > 3 What are Branches of Chemistry? Organic chemistry – study matter that contains the element carbon Inorganic chemistry – study matter that does not contain the element carbon (non-carbon) Biochemistry – bio = life, chemical processes in living things Physical chemistry– mechanism of chemical reactions, rates, energy changes during chemical reaction Analytical chemistry– analyze examine parts – composition – pollutants ppm, ppb

4. 1.2 Chemistry and You > 4 Chemistry is the study of ….  What matter is made of  how matter and energy change during chemical reactions –Examples of chemical reactions  lighting a match  digesting food to release energy  Corroded metal  Raw egg to cooked egg

5. 1.2 Chemistry and You > 5 What are Big Ideas or Common Themes in Chemistry? Central science – chemistry overlaps with all other sciences Electrons and the structure of atoms- the arrangement of electrons on atoms determines how they react with one another Bonding and Interactions- –most elements exist in compounds –the chemical bonds influence their properties Reactions – chemical reactions involve processes in which reactants form products

6. 1.2 Chemistry and You > 6 What are Big Ideas or Common Themes in Chemistry? Kinetic theory –particles of matter are in constant motion which determines their state, solid, liquid, gas Mole and Quantifying Matter- mole the unit used by chemists for specifying an amount of matter Matter and energy- the energy changes that occur during chemical reactions Carbon Chemistry- there are over 10 million carbon- containing compounds!

7. 1.2 Chemistry and You > 7 Daily question Which big ideas of chemistry are involved in roasting a marshmallow? Big Ideas of chemistry Central science Electrons and the structure of atoms Bonding and Interactions Reactions Kinetic theory Mole and Quantifying Matter Matter and energy Carbon Chemistry

8. 1.2 Chemistry and You > 8 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Why Study Chemistry? What are three general reasons to study chemistry?

9. 1.2 Chemistry and You > 9 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Why Study Chemistry? ANSWER Chemistry can be useful in explaining the natural world, preparing people for career opportunities, and producing informed citizens.

10. 1.2 Chemistry and You > 10 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Why Study Chemistry? Explaining the Natural World Chemistry can help you satisfy your natural desire to understand how things work. For example, chemistry can explain: why cut apples turn brown upon exposure to air. why the texture of eggs changes from runny to firm as eggs are boiled. why water expands as it freezes. why sugar dissolves faster in hot water than in cold water. why yeast makes bread dough rise.

11. 1.2 Chemistry and You > 11 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Why Study Chemistry? Preparing for a Career Chemists contribute to society in many ways. You do not need to have the word chemist in your job title to benefit from understanding chemistry. A reporter may be asked to interview a chemist to gather background for a story.

12. 1.2 Chemistry and You > 12 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Why Study Chemistry? Preparing for a Career Chemists contribute to society in many ways. You do not need to have the word chemist in your job title to benefit from understanding chemistry. Turf managers have the important task of keeping the grass on golf courses, lawns, and soccer fields healthy.

13. 1.2 Chemistry and You > 13 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Why Study Chemistry? Preparing for a Career Chemists contribute to society in many ways. You do not need to have the word chemist in your job title to benefit from understanding chemistry. A firefighter must know which chemicals to use to fight different types of fires.

14. 1.2 Chemistry and You > 14 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Why Study Chemistry? Being an Informed Citizen Industry, private foundations, and the federal and state government all provide funds for scientific research. Space exploration research could not take place without federal funding. NASA research has led to the development of many items used on Earth. These include smoke detectors, scratch-resistant plastic lenses, heart monitors, and flat-screen televisions. What if all the money spent on space exploration was used to find a cure for cancer?

15. 1.2 Chemistry and You > 15 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Why Study Chemistry? Being an Informed Citizen You may vote directly on some issues through ballot initiatives or indirectly through the officials you elect. You will need to make choices that will influence the direction of scientific research.

16. 1.2 Chemistry and You > 16 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Why Study Chemistry? Being an Informed Citizen When it comes to scientific research, there is no one correct answer. However, knowledge of chemistry and other sciences can help you evaluate the data presented, arrive at an informed opinion, and take appropriate action.

17. 1.2 Chemistry and You > 17 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Which of the following careers would require some understanding of chemistry? A.Chef (raise right hand) B.Doctor (raise left hand) C.Farmer (stand up) D.all of the above (just sit there)

18. 1.2 Chemistry and You > 18 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Which of the following careers would require some understanding of chemistry? A.chef B.doctor C.farmer D.all of the above

19. 1.2 Chemistry and You > 19 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Chemistry, Technology, and Society What are some outcomes of modern research in chemistry?

20. 1.2 Chemistry and You > 20 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Many basic items you use every day, such as the sneakers you wear or the cereal you eat, are products of technology. Chemistry, Technology, and Society Technology is the means by which a society provides its members with those things needed and desired.

21. 1.2 Chemistry and You > 21 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Modern research in chemistry can lead to technologies that aim to benefit the environment, conserve and produce energy, improve human life, and expand our knowledge of the universe. Chemistry, Technology, and Society

22. 1.3 Thinking Like a Scientist > 22 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. In 1928, Alexander Fleming, a Scottish scientist, noticed that the bacteria he was studying did not grow in the presence of a yellow- green mold. CHEMISTRY & YOU How do you think Alexander Fleming tested his hypothesis?

23. 1.3 Thinking Like a Scientist > 23 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. The Scientific Method What are the steps in the scientific method?

24. 1.3 Thinking Like a Scientist > 24 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. The Scientific Method The scientific method is a logical, systematic approach to the solution of a scientific problem.

25. 1.3 Thinking Like a Scientist > 25 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. The Scientific Method Steps in the scientific method include making observations, proposing and testing hypotheses, and developing theories.

26. 1.3 Thinking Like a Scientist > 26 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. The Scientific Method Making Observations Suppose you try to turn on a flashlight and you notice that it does not light.

27. 1.3 Thinking Like a Scientist > 27 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. The Scientific Method Testing Hypotheses A hypothesis is a proposed explanation for an observation. If you guess that the batteries in a flashlight are dead, you are making a hypothesis.

28. 1.3 Thinking Like a Scientist > 28 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. The Scientific Method Replacing the batteries is an experiment, a procedure that is used to test a hypothesis. Testing Hypotheses

29. 1.3 Thinking Like a Scientist > 29 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. The Scientific Method Replacing the batteries is an experiment, a procedure that is used to test a hypothesis. The variable that you change during an experiment is the independent variable, also called the manipulated variable. The variable that is observed during the experiment is the dependent variable, also called the responding variable. Testing Hypotheses

30. 1.3 Thinking Like a Scientist > 30 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. The Scientific Method For the results of an experiment to be accepted, the experiment must produce the same result no matter how many times it is repeated, or by whom. This is why scientists are expected to publish a description of their procedures along with their results. Testing Hypotheses

31. 1.3 Thinking Like a Scientist > 31 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. The Scientific Method Sometimes the experiment a scientist must perform to test a hypothesis is difficult or impossible. For example, atoms and molecules, which are some of the smallest units of matter, cannot be easily seen. A model is a representation of an object or event. Chemists may use models to study chemical reactions and processes. Testing Hypotheses

32. 1.3 Thinking Like a Scientist > 32 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. The Scientific Method Developing Theories Once a hypothesis meets the test of repeated experimentation, it may be raised to a higher level of ideas. It may become a theory. A theory is a well-tested explanation for a broad set of observations.

33. 1.3 Thinking Like a Scientist > 33 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. The Scientific Method A scientific law is a concise statement that summarizes the results of many observations and experiments. A scientific law states what happens, it doesn’t try to explain the relationship it describes. A scientific theory explains why things occur. Scientific Laws

34. 1.3 Thinking Like a Scientist > 34 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. The figure below shows how scientific experiments can lead to laws as well as theories. The Scientific Method Scientific Laws Experiments An experiment can lead to observations that support or disprove a hypothesis. Theory A theory is tested by more experiments and modified if necessary. Hypothesis A hypothesis may be revised based on experimental data. Observations Scientific Law A scientific law summarizes the results of many observations and experiments.

35. 1.3 Thinking Like a Scientist > 35 Parts of the scientific method observation – which generates a question. Flashlight doesn’t turn on Question – what is wrong with the flashlight? Infer-(prediction) that batteries, lightbulb not working Hypothesis – (written as an “If … “then” ….. statement) “If the batteries are replaced with new ones, then the flashlight will work.” Experiment – test of the hypothesis – replace the batteries in the flashlight and see if it works. Independent variable (manipulated variable) – batteries Dependent variable (responding variable) - light working or not

36. 1.3 Thinking Like a Scientist > 36 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. What is a hypothesis? A.information obtained from an experiment B.a proposed explanation for observations C.a concise statement that summarizes the results of many experiments D.a thoroughly tested model

37. 1.3 Thinking Like a Scientist > 37 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. What is a hypothesis? A.information obtained from an experiment B.a proposed explanation for observations C.a concise statement that summarizes the results of many experiments D.a thoroughly tested model

38. 1.3 Thinking Like a Scientist > 38 What theory am I???

39. 1.3 Thinking Like a Scientist > 39 Fossil of glossopteris fern found on Antarctica

40. 1.3 Thinking Like a Scientist > 40 Fossil of lystrosaurus found on South America & Africa- yet it could not swim!

41. 1.3 Thinking Like a Scientist > 41 Continents seem to fit together

42. 1.3 Thinking Like a Scientist > 42 What Theory Am I? Continental Drift Proposed by Alfred Wegner

43. 1.3 Thinking Like a Scientist > 43 What theory am I??? Mid-Atlantic Ridge

44. 1.3 Thinking Like a Scientist > 44 Seafloor spreading evidence What theory am I???

45. 1.3 Thinking Like a Scientist > 45 Evidence from Age of rocks along Mid-Atlantic Ridge: youngest rocks are closest to it What theory am I ???

46. 1.3 Thinking Like a Scientist > 46 What Theory Am I? Put all the clues together fossil evidence Fit of continents Mid-Atlantic Ridge Seafloor spreading Age of rocks along Mid-Atlantic Ridge Magnetic reversals

47. 1.3 Thinking Like a Scientist > 47 Theory of Plate Tectonics

48. 1.3 Thinking Like a Scientist > 48 Section 1.4 - Steps to Problem Solving

49. 1.3 Thinking Like a Scientist > 49 PROBLEM SOLVING Analyze Where are you starting? - write down known information Where are you going? – write down unknown information, include the units Draw pictures of diagrams to help Calculate – crunch the numbers Evaluate – look at the answer. Does it make sense? Should it larger/smaller than starting? Does it have correct units?

50. 1.3 Thinking Like a Scientist > 50 25. There is an ice cream shop six blocks north of your hotel. How many minutes will it take to walk there and back? Use the information from the sample problem. Analyze known information – 6 blocks, there & back = 12 blocks Unknown information – time in minutes Calculate Evaluate

51. 1.3 Thinking Like a Scientist > 51 25. There is an ice cream shop six blocks north of your hotel. How many minutes will it take to walk there and back? Use the information from the sample problem. Analyze known information – 6 blocks, there & back = 12 blocks Unknown information – time in minutes Calculate Evaluate

52. 1.3 Thinking Like a Scientist > 52 Steps of the scientific method 1.Observation 2.Hypothesis 3.experiments

53. 1.3 Thinking Like a Scientist > 53 mixtures Heterogeneous (hetero = other or different) Italian salad dressing Homogeneous Uniform mixtures Example - Solutions which are clear

54. 1.3 Thinking Like a Scientist > 54 Separating mixtures Distillation – used for homogeneous mixtures Liquid is boiled to produce a vapor which is cooled into a liquid

55. 1.3 Thinking Like a Scientist > 55 Filtration Separates solid insoluble components out of heterogeneous mixtures Water filtration Separating mixtures

56. 1.3 Thinking Like a Scientist > 56 Elements Found on periodic table- 92 in nature Simplest form of matter that has a unique set of properties Can’t be broken down – no longer have elements What information about elements is provided on your periodic table?

57. 1.3 Thinking Like a Scientist > 57 compounds Made from elements that are chemically combined or chemically bonded together Can you name these compounds? CO 2 – H 2 O - CO – Compounds can be broken down by chemical changes (chemical reactions)

58. 1.3 Thinking Like a Scientist > 58 Clues to Chemical reactions (chemical changes) Reactants Products (ARROW POINTS TO PRODUCTS) What are the clues to these chemical reactions? Light match Acid & seashells Litmus paper KI & PbNO 3 How do the pictures in Figure 2.15 indicate chemical changes have occurred?

59. 1.3 Thinking Like a Scientist > 59 Law of Conservation of Mass The law of conservation of mass states that the mass of the reactants before a chemical reaction will be equal to the mass of the products after a chemical reaction. Draw a picture to show the Law of Conservation of Mass How did the seashell and acid reaction show this?