Nature of Science

1. Nature of Science

3. What is the “Nature of Science”

4. Lab Equipmentt

5. Lab Equipment

6. Identify Lab Glassware

7. Beakers Flasks

8. Answer Lab Equipment Graduated cylinders are marked in units called what? • grams • liters • milliliters • millimeters Answer: milliliters (mL)

9. Lab Equipment Which of the following measures volume? a. Kilogram b. Square kilometer c. Liter d. Cubic centimeter Answer: c and d Important to know: 1cm 3 = 1mL

10. Graduated Cylinder Measures liquids or “volume” Volume = amount of space something occupies Labeled in mL (milliliters)

11. Know how to read a graduated cylinder “Meniscus”

12. Properties of Matter A person is trying to identify a chemical and decides to determine if it has an odor because this is a property of matter. What method should he use? • Smelling • Touching • Inhaling • Wafting Answer: Wafting

13. “Wafting” is the method used to smell a chemical in the lab

14. Balance Scale Which instrument is used when finding the mass of an object? • Spring Scale • Balance Scale • Graduated Cylinder • Metric Balancing Stick Answer: Balance Scale

15. Balance Scale • Measures “mass” • Mass is amount of matter • Labeledg= grams

16. Review

18. Safety What is the correct method in picking up hot glassware? a. With your hands b. With the cloth on your lab coat c. With heat-resistant gloves d. With any type of lab gloves Answer: With heat-resistant gloves

19. Safety When should you report a spill or breakage to your teacher? • after you’ve cleaned up the mess • only if you think it is dangerous • immediately • after you finish the investigation Answer: Immediately

20. Safety Answer # 3 Which type of safety equipment would always be used during the testing of a chemical reaction? • safety goggles • gloves • lab coat • ear plugs Answer: safety goggles

21. Safety Goggles Lab Coat Gloves Shoes

22. Investigation Any factor that can change DURING an experiment is a • data table. • control. • hypothesis. • variable. Answer: variable

23. Independent –vs- dependentVariables

25. Variable and Hypothesis Which of the following is the BEST variable to control when testing the hypothesis; “Does the concentration of salt in water effect the rate at which it freezes?” • Temperature • Time • Concentration of salt • Type of containers Answer: Type of containers

26. Variables Identify the flaw in the following experiment. A student Asked three friends to put some trays in their freezers, some would have hot water and some would have cold water. They would then time how long it takes for each tray to freeze solid, and then call him to give their results. • There are too many variables that could affect the results of the test. • There were no time limits given to complete the test. • There is no benefitto this test. • There will be no quantitative data to collect by the students. Answer: There are too many variables

27. Independent Variable • In thishypothesis, which of the following is the independent variable? “Does the concentration of salt in water effect the rate at which it freezes?” • a.Temperature • b. Time • c. Concentration of salt • Type of container • Answer: Concentration of salt

28. Manipulated Variable A manipulated variableis also called the “independent”variable and is the variable that is altered or changed in an experiment. It is what “you” change. Example; your trying to see what paper towel would be more absorbent, your manipulated variable would be Answer: the type of paper towel you use • Always ask: What was intentionally changed?

29. Dependent Variable The dependent variable is the factor that responds to changes in the independent variable. Example: Which fertilizer grows the largest apples? Independent: type of fertilizer used Dependent: size of apples that are grown (volume or mass of apples)

30. Independent –vs- dependentVariables

31. Dependent Variable Which of the following is the dependent variable given the hypothesis; “Does the concentration of salt in water effect the rate at which it freezes?” • Temperature • Time • Concentration of salt • Type of container Answer: Time

32. Independent Variable A scientist plans to test the effect temperature has on the density of salt water. What is the independent variable? • density • temperature • Salinity • depth of water Answer: density

33. Dependent Variable A scientist plans to test the effect temperature has on the density of salt water. What will the manipulated (dependent) variable be? • density • temperature • Salinity • depth of water Answer: temperature

34. Dependent Variable In and experiment designed to determine conditions favorable for growing tomato plants, one group of tomato plants is exposed to constant light and fixed amounts of water. Another group of tomato plants is given varying amount of light and water. In this experiment, the dependent variable is. a. Sunlight b. Water c. The growth of the tomato plant d. The quality of the soil Answer: The growth of the tomato plant

35. Graphing

38. Graphing

39. Hypothesis What is an hypothesis? • A factor that changes in an experiment • A statement that describes what will happen in an experiment. • A statement that explains what has been or is about to be tested • A statement that explains what has been learned. Answer: A statement that explains what has been or is about to be tested

40. Inference What of the following is an inference? • For lunch we will have pizza • In two weeks it will snow. • The temperature today is 27oC • I smell smoke coming from the woods Answer: In two weeks it will snow.

41. Observations • Which of the following is a quantitative observation? • The bag contains five rocks. • The bag contains pretty rocks. • The bag is heavy. • The bag smells bad. • Answer: Bag with “five” rocks

42. Why do scientists use the scientific method? In order to solve problems and answer questions.

45. Scientific Method A possible answer to a question that can be tested through experiments. • hypotheses • conclusion • observation • Inference Answer: hypotheses

46. Steps of Scientific Method After conducting an experiment and making a conclusion, the next MOST LIKELY step would be to… • construct a data table and graph. • think of a hypothesis. • report the findings. • design a new experiment. Answer: report the findings 

47. Scientific Method Which of the following can not be measured using the scientific method? • Why is the sky blue? • Why do frogs croak at night? • Which brand of paper towels is the most absorbent? • Which brand of paper towels is the best? Answer: Which brand of paper towels is best?

48. (Repeat) Scientific Method Any factor that can change DURING an experiment is a • data table. • control. • hypothesis. • Variable Answer: variable

49. Scientific Method The part of the experimental design that does not change from setup to setup is called what? • control • variable • constant • hypothesis Answer: Control

50. Scientific Method / Control A scientific investigation is designed to test the effects of salt on the freezing point of water. What is the control group for this investigation? • Tap water with nothing added to it. • Tap water with 1 cup of salt added to it. • Ocean water with 1 cup of salt added to it. • Ocean water with nothing added to it. Answer: Tap water with nothing added to it.