Chapter 1 Review

1. Chapter 1 Review 2013

2. Precision and Accuracy How do these terms in science differ from their everyday meanings?

3. Precision and Accuracy How do these terms in science differ from their everyday meanings? • precision is the exactness of a measurement • accuracy is how close the value is to a true value • The terms are not interchangeable in science as they may be in everyday language.

4. Physical science was once defined as “the science of the nonliving world.” Explain why that definition is no longer sufficient.

5. Physical science was once defined as “the science of the nonliving world.” Explain why that definition is no longer sufficient. As knowledge has increased, scientists have learned that the discoveries in one area are applicable to another. For example, the study of the chemistry (a physical science) of living things is biochemistry.

6. Explain why the observation that the sun sets in the west is a scientific law.

7. Explain why the observation that the sun sets in the west is a scientific law. It has been observed repeatedly and does not attempt to explain why the sun sets in the west.

8. Explain why the following statement could be considered a scientific theory: The rotation of the Earth causes the sun to set.

9. Explain why the following statement could be considered a scientific theory: The rotation of the Earth causes the sun to set. The rotation of the Earth causing the sun to set could be considered a scientific theory because it is a tested, possible explanation of why the sun sets in the west.

10. What is mass and how does it differ from weight?

11. What is mass and how does it differ from weight? Mass is quantity of matter, whereas weight is the force with which Earth’s gravity pulls on that quantity of matter. Mass is constant throughout the universe. Weight changes with location (depends on the pull of gravity). The further you get from the center of the Earth, the less you weigh. (i.e., on a mountaintop you weigh less than at sea level).

12. Some features on computer chips can be as small as 35 nm. Explain why you would use scientific notation to express this quantity in meters.

13. Some features on computer chips can be as small as 35 nm. Explain why you would use scientific notation to express this quantity in meters. Scientific notation would be used to express 35 nm in terms of meters because it is 0.0000000035 m. Using scientific notation decreases the number of zeros that need to be written and decreases the possibility of errors in calculations.

14. The mass of a certain elephant is 3476 kg. A zoologist who measures the mass of that elephant finds the mass to be 3480 kg. Is the mass measured by the zoologist accurate?

15. The mass of a certain elephant is 3476 kg. A zoologist who measures the mass of that elephant finds the mass to be 3480 kg. Is the mass measured by the zoologist accurate? The measured mass of the elephant is accurate because it is very close to the actual mass of the elephant. The instrument used by the zoologist just was not as precise as the instrument used to determine the true value.

16. Which branch of science is not included in physical science? A. physics B. chemistry C. astronomy D. zoology

17. Which branch of science is not included in physical science? A. physics B. chemistry C. astronomy D. zoology Do you agree with this answer? Why or why not?

18. Which science deals most with energy and forces? A. biology B. physics C. botany D. agriculture

19. Which science deals most with energy and forces? A. biology B. physics C. botany D. agriculture

20. Using superconductors to build computers is an example of A. technology B. applied biology C. pure science D. an experiment

21. Using superconductors to build computers is an example of A. technology B. applied biology C. pure science D. an experiment

22. A balance is a scientific tool used to measure A. temperature B. time C. volume D. mass

23. A balance is a scientific tool used to measure A. temperature B. time C. volume D. mass

24. Which unit is an SI base unit? A. liter B. cubic meter C. kilogram D. centimeter

25. Which unit is an SI base unit? A. liter B. cubic meter C. kilogram D. centimeter

26. The composition of the mixture of gases that make up our air is best represented by a: A. pie graph B. bar graph C. line graph D. scatter plot

27. The composition of the mixture of gases that make up our air is best represented by a: A. pie graph B. bar graph C. line graph D. scatter plot

28. In a controlled experiment, A. the outcome is controlled B. one variable remains fixed, and the other variables are changed C. you change one variable throughout the experiment, and the other variables remain fixed D. results are obtained by computer models

29. In a controlled experiment, A. the outcome is controlled B. one variable remains fixed, and the other variables are changed C. you change one variable throughout the experiment, and the other variables remain fixed D. results are obtained by computer models

30. Written in scientific notation, 0.000060 s is: A. 60 s B. 6.0 x 10-5 s C. 6.0 x 10-6 s D. 6.0 x 104 s

31. Written in scientific notation, 0.000060 s is: A. 60 s B. 6.0 x 10-5 s C. 6.0 x 10-6 s D. 6.0 x 104 s

32. When studying a molecule, a chemist make a model of the molecule to: A. know the outcome of the experiment B. help visualize the model C. measure the mass of the molecule D. observe the results of a chemical reaction

33. When studying a molecule, a chemist make a model of the molecule to: A. know the outcome of the experiment B. help visualize the model C. measure the mass of the molecule D. observe the results of a chemical reaction

34. The maximum depth of a certain lake is 244 m. What is the depth in km? A. 0.0244 km B. 0.244 km C. 24,400 km D. 244,000 km Dimensional Analysis work: 244 m x 1 km = 0.244 km 1000 m

35. The maximum depth of a certain lake is 244 m. What is the depth in km? A. 0.0244 km B. 0.244 km C. 24,400 km D. 244,000 km

36. Do scientific laws ever change? Explain.

37. Do scientific laws ever change? Explain. Scientific laws can change. They are based on the results of many experiments and observations. If a new discovery that cannot be predicted by a law is confirmed by repeated experiments, the law may need to be modified to explain the new discovery.

38. Explain whether or not scientific methods are sets of procedures that scientists follow.

39. Explain whether or not scientific methods are sets of procedures that scientists follow. Scientific methods are not exact sets of procedures that scientists follow. They are guidelines that describe the process of finding answers in a scientific way, but the exact procedures may vary depending on the questions to be answered.

40. INTERPRETING GRAPHICS - Which variable is the dependent variable? - Which variable is the independent variable? - Why was this data presented in a line graph?

41. INTERPRETING GRAPHICS Temperature During a Chemical Reaction” (graph-page 37) - Which variable is the dependent variable? Temperature is the dependent variable because temp. depends on the time and temperature is on the y-axis. - Which variable is the independent variable? Time is the independent variable because it’s value does not depend on what happens in the experiment and it is on the x-axis.

42. INTERPRETING GRAPHICS Temperature During a Chemical Reaction” (graph-page 37) - Why was this data presented in a line graph? A line graph was used because the temperature changed continuously with time during the experiment.

43. Critical Thinking Applying Ideas: Today, scientists must search through scientific journals before performing an experiment or making methodical observations. Where would this step take place in a diagram of scientific methods? This step would take place in the research and data collection step.

44. Critical Thinking Applying Ideas: Today, scientists must search through scientific journals before performing an experiment or making methodical observations. Where would this step take place in a diagram of scientific methods?

45. Critical Thinking Evaluating Assumptions At an air show, you are watching a group of sky divers when a friend says “We learned in science class that things fall to Earth because of the law of gravitation.” What is wrong with your friend’s statement? Explain your reasoning.

46. Evaluating Assumptions The law of gravitation states that objects fall to Earth; it even shows how to calculate the force. It does not explain why.

47. Applying Concepts You report that a friend can go exactly 500 m on a bicyle in 39.46 s. But your stopwatch runs 2 s fast. Explain how your stopwatch affects accuracy and precision of your measurement.

48. Applying Concepts You report that a friend can go exactly 500 m on a bicyle in 39.46 s. But your stopwatch runs 2 s fast. Explain how your stopwatch affects accuracy and precision of your measurement. Because my stopwatch runs 2 s fast, the time I measured is not accurate. However, the stopwatch can measure to one hundredth of a second, so my measurement is precise.

49. Graphing Skills The bar graph below summarizes how a consumer magazine has rated several stereos by price and sound quality. a. Which brand do you think has the best sound for the proce? b. Do you think that sound quality is truly related to price? Explain your answer.

50. Graphing Skills a. Which brand do you think has the best sound for the price? Walsonic b. Do you think that sound quality is truly related to price? Explain your answer. No. If sound quality and price were equal for all of the companies, then sound quality and price would be related. The graph shows these two properties change relative to one another depending on the company, so sound quality and price are not truly related.