1. The Nature of Science

2. Something to Think About  Scientific research is the leading cause of cancer in lab rats…

3. The Goal of Science  The goal of science is to investigate and understand nature, to explain events in nature, and to use those explanations to make useful predictions.

4. Scientific Methods  Scientific Methods are:  The common steps scientists use to gather information and answer questions.  An organized set of investigation procedures.  Six common steps  May need to skip, repeat, or add steps depending on the situation.

5. Scientific Methods  State the problem in the form of a question  Research and gather information  Form a hypothesis  an educated guess;  a possible explanation based on what you observe or already know  written in “If…then…” format and should be a complete, stand-alone sentence.

6. Scientific Methods  Set up a controlled experiment;  to test your hypothesis  control variables  Collect and analyze data;  use tables and graphs  Draw conclusions;  Evaluate your results to see if your hypothesis was correct.

7. State the problem Gather information Form a hypothesis Test the hypothesis Analyze data Draw conclusions

9. Controlled Experiment  Variable - any factor in an experiment that can change  Temperature, time, amount of light, etc.  Only allow one variable to change per experiment  Control group – group in an experiment in which all conditions are kept the same; no variables are applied  Used for comparison ; ensures that the tested variable is what causes the results

11. Types of Variables  Independent Variable – factor that affects the measure of another variable as it changes  The variable you will manipulate/change  Graphed on the x-axis  Dependent Variable – factor that changes as a result of changes in the independent variable  The variable you will measure  Graphed on the y-axis

12. Identify the Variables  Dependent variable?  Independent variable?  Control group? Plant Amount of Water Amount of Sun Fertilizer Type Height after two weeks A 4 oz. every three days6hr/dayA16cm B 4 oz. every three days6hr/dayB14cm C 4 oz. every three days6hr/dayC18cm D 4 oz. every three days6hr/daynone10cm amount of growth fertilizer type no fertilizer (plant D)

13. Science Terms  Theory – an explanation of things or events based on knowledge gained from many observations/investigations  Not just a guess  Can be used to explain a scientific law  Law – statement about what happens in nature that seems to be true all of the time  Does not explain how or why

14. Self-Check (1.1) If you perform an experiment to see if a new vitamin supplement would cause your hair to grow faster… 1)What is the dependent variable? 2)What is the independent variable? 3)Why do you need a control group? 4)What would your control group be? 5)How would you set up the experiment?

15. Cut out 10 rectangles  Which one shows the main topic?  Which 6 are the steps of the scientific methods?  Place them in order (first to last)  Which are types of variables?  If Sam tests the effect that temperatures (high and low) have on the volume of a gas:  What is the temperature in this experiment?  What is the volume of the gas in it?  What should he use as a comparison?

16. Measurement in Science The standards

17. Did You Know…  An inch (2.5 centimeters) of rain water is equivalent to 15 inches (38.1 centimeters) of dry, powdery snow.  The highest temperature produced in a laboratory was 920,000,000 °F (511,000,000 °C) at the Tokamak Fusion Test Reactor in Princeton, NJ.

18. Units and Standards  How many “hands” across is your desk?  A “hand” is the distance from your thumb to your pinky finger.  Why do you suppose we need a standard way to measure things?  A standard is an exact quantity that people agree to use to compare measurements.

20. Metric System  In science, we will use the metric system  based on multiples of ten  International System of Units  All SI standards are universally accepted and understood by scientists throughout the world.  Each type of SI measurement has a base unit with its own unique symbol.

22. μ

23. Converting Units  2 main ways  Use a conversion factor  For example, there are 1,000 mL in 1 L, so 1,000 mL = 1 L.  1,000 mL/1 L = 1  Move decimal (based on multiples of 10)  K H D B D C M  For example, 10 cm = 0.1 m

24. Conversion Factors  Use the conversion factor with new units (mL) in the numerator and the old units (L) in the denominator.

25. Measurement in Science  Length – the distance between two points  Units:  SI unit: meter (m)  Other common units: mm, cm, km  Tool: meter stick

26. Measurement in Science  Volume – the amount of space an object takes up  Units (may be derived):  Liquids: liter (L);  Solids: cubic meters (m 3 ) or cubic centimeters (cm 3 )  Tools: meter stick or graduated cylinder Note: 1 mL = 1 cm 3

27. Measurement in Science  Mass – the amount of matter in an object  Units:  SI unit: kilogram (kg)  Other common units: g, mg  Tools: scale or triple-beam balance

28. Measurement in Science  Density – mass per unit volume  Units (derived): g/cm 3 or g/mL  Tool: varies

29. Measurement in Science  Temperature  Units:  SI unit: Kelvin  Other unit: Celsius  Note: K=°C+273  Tool: Thermometer

30. Mass and Weight  Don’t confuse mass with weight  Weight is the measure of the pull of gravity on the mass of an object  The mass of an object does not change from one place to another, but its weight will change depending on gravity  A 10 gram block will have a mass of 10 grams on Earth and on the moon, but it would weigh less on the moon because the pull of gravity is less.

31. Self-Check (1.2) 1.How many meters are in 3.45 km? 2.2.4 g = ______ mg 3._______ mL = 32 L 4.24°C = ______ K 5.1 cm = _____ mm 6.0°C = ______ K

32. Reinforcing Activities  http://www.brainpop.com/science/matt erandchemistry/measuringmatter/ http://www.brainpop.com/science/matt erandchemistry/measuringmatter/

33. Communicating in Science

35. Graphing  A graph is a visual display of information or data.

36.  The x-axis (horizontal):  Measures time on this graph  The independent variable Graphing

37.  The y-axis (vertical):  Measures distance on this graph  The dependent variable Graphing

38. Line Graphs  Line graphs – show the relationship between the dependent variable and the independent variable.

39. Bar Graphs  Bar graphs – compare information collected by counting

40. Constructing Graphs  Use the x-axis for the independent variable.  Use the y-axis for the dependent variable.  Give your graph a descriptive title.  Label both the x and y axis AND make sure you write the appropriate units.  Make sure that the graph fills the whole graphing area (not just the left corner).

42. Circle (Pie) Graphs  Circle graph – shows how a fixed quantity is broken down into parts.  The circular pie represent the total.  The slices represent the parts.  usually in percentages of a total  should add to 100%  Needs a descriptive title with labels and units for each pie piece.  Make sure that pieces are appropriately sized.

43.  This graph starts with 72 buildings.  For each type of fuel, you divide the number of buildings using each type by the total (72).  Example: 18 use steam so 18/72=0.25=25%

44. Self-Check (1.3) 1.Draw 2 different graphs to represent the data to the right (shapes). 2.Draw a line graph to represent the data to the right (distance). Shapes in a Bag Squares5 Circles2 Triangles3 Distance in Race Start0 m 10 seconds20 m 20 seconds40 m

45. Reinforcing Activities  http://www.brainpop.com/math/dataan alysis/graphs/ http://www.brainpop.com/math/dataan alysis/graphs/