2.  Geophysical Science (Earth Science) has four major branches: 1. Geology 2. Astronomy 3. Meteorology 4. Oceanography What does each branch study?

3.  We will be looking at the details of the four branches while seeing how the four “spheres” interact.  Making a change in one sphere will influence another sphere.  This relationship between the spheres and the study of their interactions is called Earth System Science.

4.  The Four Major “Spheres”:  Atmosphere- layer of gasses surrounding Earth.  Biosphere- all life found on Earth.  Hydrosphere- all water found on Earth.  Lithosphere (geosphere)- rigid outermost shell (rocky portion) of Earth.

5.  Earth is a closed system in terms of matter. -Matter moves between the different spheres without being created or destroyed. -As it moves through different spheres it can change form (from one compound to another). It can also change state of matter (from a liquid to a solid or a liquid to a gas, for example).

6.  Observation is using your 5 senses to know or determine something.  Different observers exposed to the same sense do not necessarily see, hear, feel, taste or smell the same things.

7.  An inference is making an explanation for the observation.  An inference is reached on the basis of evidence and reasoning (an inference is similar to an assumption).  Inferences express probability, not certainty.  Example: There is steam rising off the cup of coffee (observation). The coffee is hot (inference).

8. 1.Ask a Question. Come up with a question that you will attempt to answer through your experiment. Make sure you phrase it as a question! Example: How does the temperature of water affect dissolve time of an alka seltzer tablet?

9. 2.Gather Information. Do some research on the topic of your study. Use books, the internet, peers, and personal knowledge to provide some background information. Also include information if anyone has ever done this experiment before and, if so, what their results were.

10. 3.Make a Hypothesis.  Come up with a prediction, or an informed statement, that answers the question you asked (usually if/then format). Example: If I dissolve alka seltzer tablets in water of varying temperatures, then the highest temperature water will dissolve the tablet fastest.  Do not use “I think …” or “Maybe…” This is your prediction … make it a strong statement. It’s okay if it is wrong.

11. 4. Perform the Experiment. List the procedure that you will follow (along with the materials used) to do the experiment (MATERIALS/METHODS). Example: 1.Obtain 5 alka seltzer tablets and 5 glasses that are the same size. 2.Fill each glass with the same amount of water. Glass 1 water temperature should be 10°, water in glass 2 should be 20° (room temp.), water in glass 3 should be 30°, water in glass 4 should be 40° and water in glass 5 should be 50°. 3.Place an alka seltzer tablet in each glass and, without stirring, record the time it takes for the tablet to completely dissolve (start the stop watch when the tablet goes into water and stop timing when tablet is completely dissolved). 4.Record the dissolve times at each temperature in a data table. 5.Repeat this experiment 5 times.

12.  The best way to perform an experiment is to limit the number of variables. The fewer the variables the more meaningful the results.  However, every experiment will at least have two variables:  The Independent Variable – The one the experimenter manipulates (the variable that’s intentionally changed by experimenter).  The Dependent Variable – The one that is affected by the independent variable, and not directly controlled by the experimenter (the dependent variable depends on (will change in response to) the independent variable).

13.  In the example provided, what is the…  Independent Variable?  The water temperature (the experimenter controls the water temperature in each glass).  The levels of the independent variable are the different values of the independent variable, such as using water at 10°, 20°, 30°, 40°, and 50° C. The levels of the independent variable can also be thought of as the experimental groups that are set up.  Dependent Variable?  The time it takes for the alka seltzer tablet to dissolve  This is not controlled by the experimenter. Rather, the dissolve time will DEPEND ON the temperature of the water.

14.  The control (control group) is the standard against which the experimenter compares the results from each experimental group in the experiment.  For example, the control might be the room temperature water, which is about 20°C. In this case, all other water temperatures would act as the experimental groups and would be compared against the room temperature water.  In many cases, there will not be a true control. The researcher could then set one of the groups as the standard and measure the other groups against that standard.

15.  Can blueberries slow down aging? A study indicates that antioxidants found in blueberries may slow down the process of aging. In this study, 19-month old rats (equivalent to 60-year old humans) were fed either their standard diet or a diet supplemented by either blueberry, strawberry, or spinach powder. After eight weeks, the rats were given memory and motor tests. Although all supplemented rats showed improvement, those supplemented with blueberry powder showed the most notable improvement.

16. What is the independent variable?  Diet (blueberries, etc…) What is the dependent variable?  Motor/Memory Test Results

17.  In order to test a variable in an experiment, a comparison must be made to whatever has not been subjected to the variable. This is referred to as a control, or control group.  In order to have a controlled experiment, you must have a control group.  The group that receives the variable, is the experimental group.  What is the control group from the previous example? Control Group: Rats fed a standard diet!

18. 5.Collect and Analyze Data.  Data is always collected in a table or chart.  Data is always presented in a graph. (line or bar) more to come on this! Example of a data table  Example of a line graph 

19. 6.Make a Conclusion. Your conclusion must do two important things – 1) Explain in words what your graph shows and… 2) State whether your results did or did not support your hypothesis (if your hypothesis is partially true or untrue, go back to “gather information” step and proceed through steps of scientific method again). Example: After repeating this experiment 5 times, the data showed the hottest water (50°C) dissolved the tablets in the least amount of time. The results show that my hypothesis was correct. The higher temperature water will dissolve the tablet in the least amount of time. The opposite was true for the coolest water (10°C) in which the tablet took the longest time to dissolve.

20. 7.Communicate your findings.  Write up a lab report in which you address each step of the scientific method. Be sure to include graphs and tables when needed. Your report should follow the steps in the same order as we have covered them.

21. An Easy Way to Remember the Scientific Method… Queens In Heels Eat Delicious Chocolate Cake!!! Queens= question In= information Heels= hypothesis Eat= experiment Delicious= data Chocolate= conclusion Cake= communicate

22.  Ideas or phenomenon that have been tested many times (and many observations have been made) are often given explanations.  These explanations, found in many observations and experiments, are called theories. Theories must be supported by a great deal of evidence.

23.  When setting up a graph it is important to keep in mind that a graph is a visual picture of the data.  LOOKS COUNT when it comes to graphing.  Appropriate graphs that are scaled correctly and neatly are excellent tools for analyzing results.

24. 1. Title your graph – make an appropriate title for what is being represented (should be descriptive of data plotted). 2. Label axes – leave space for labeling each axis (INCLUDE UNITS). 3. Always plot the independent variable (control) on the horizontal (x) axis. 4. Choose an appropriate scale – make sure that each box on each axis is given the same value(1,2,5,10) and that the data will fit on the paper according to your scale, but at the same time, be visually pleasing.

25.  In this class you will be using either a line, or a bar graph, but how do you know when to use which graph?  Use a line graph when a there is a direct correlation between the two variables being plotted.  Use a bar graph when the two variables are not directly correlated.

26.  Accuracy indicates how close a measurement is to the accepted value.

27.  Precision indicates how close together or how repeatable the results are.  You can be precise, but not accurate (meaning you get the same wrong value again and again).  Ideally, you’d like to be both accurate and precise (meaning you are getting the correct value again and again).

28. Experimental Error There are many potential sources of error when designing and carrying out experiments. Errors can arise from: 1.Instrument error: Calibration of the instrument has not been carried out or is faulty. Consequently, accuracy and precision are affected. 2.Personal error: Observer making inaccurate observations. These type of errors can be overcome by taking an average based on several measurements, especially if data is collected by two or more independent observers. This overcomes the problem of personal bias resulting from poor observational habits which might produce a consistent observational error if only one investigator collects the data. 3.Sampling errors: These can also arise because of the size or nature of the sample used. Sample sizes can be either too small or not random enough. Replication of experiments also reduces errors.

29. Error Analysis One way to analyze experimental error is with a % error calculation. The % error is useful when you have a single experimental result that you wish to compare with a standard value. Utilize the following calculation: Expt # = experimental # (value you got) Std. # = standard # (accepted or correct value)

30. Sample Problem The accepted density value for Titanium is 4.5g/ml. Johnny measured Titanium’s density and received a value of 4.2g/ml. What is the percent error in his measurement? 4.2 – 4.5 x 100 = 6.7% is the percent error 4.5 NOTE: A 0% error means you got the correct accepted value. The larger the percent error value, the farther away you are from the accepted value (ideally, you want a low % error).

31.  Measuring and measurement tools are an essential part of the scientific process.  The International System of Units (SI), also called metric system, will be used in this class and in most science classes.

32.  Prefixes: (from biggest to smallest)  kilo (k)- (1,000 times bigger than base unit)  hecto (h)- (100 times bigger than base unit)  deca (dk)- (10 times bigger than base unit)  BASE UNIT (meters, liters, grams)  deci (d)- (10 times smaller than base unit)  centi (c)- (100 times smaller than base unit)  milli (m)- (1,000 times smaller than base unit)

33.  King (kilo)  Henry (hecto)  Died (deca)  By (base unit)  Drinking (deci)  Chocolate (centi)  Milk (milli)

34.  Converting in the metric system is simply an exercise in moving the decimal place. 1. You start at the prefix of your known value. 2. You move (left or right) to the prefix you are trying to find. 3. You move the decimal point in the same direction for the same number of places to find the new answer. Base unit K ilo H ecto D eca ( l,g,m ) D eci C enti M illi l = liters (unit of volume) g = grams (unit of mass) m = meters (unit of distance)

35.  How many kilometers are in 432.3 centimeters? Base unit K ilo H ecto D eca ( l,g,m ) D eci C enti M illi 1.Start at “centi” since that is our given prefix. 2.Go 5 places to left to get to kilometers (our unknown). 3.Move the decimal in our known value 5 places to left. 4.432.3 cm becomes 0.004323 km

36.  567 g = __________ mg  78 L = ___________ Kl .0078 km = _______ cm  345 m = _______ dm  7.53 dkg = ________ dg 567,000 0.078 780 3,450 753

37.  The amount of matter (mass) in a given space (volume)  Density describes how tightly packed the molecules in a substance are.  Density = mass/volume More DENSE Less DENSE

38.  In this class you will be asked to solve some problems from time to time using some equations and calculations.  To give you a way of organizing your information, I would like you to use this four step method to solve all problems in this class.

39. 1. Read the Problem and list the information given (knowns and unknowns). 2. Show the formula you will use to solve the problem. 3. Solve the problem – show your work with units included. 4. Show your answer with the correct number of decimal places, or a whole number. It is extra important that your answer also includes units. Include a circle or a box around your final answer.

40. 1. WHAT IS THE DENSITY OF AN OBJECT THAT HAS A VOLUME OF 14.3 mL, AND A MASS OF 20.0 g? Knowns/UnknownEquationShow workAnswer/units D=M/V M=20.0g V=14.3 ml D=? D=20.0g/ 14.3 ml D= 1.4 g/ml

41. 2. WHAT IS THE MASS OF AN OBJECT THAT HAS A VOLUME OF 2.0 mL, AND A DENSITY OF 10.4 g/mL? Knowns/UnknownEquationShow workAnswer/units M=D*V D=10.4 g/ml V=2.0 ml M=? M=10.4 g/ml * 2.0 ml M=20.8 g

42. 3. WHAT IS THE VOLUME OF A GAS THAT HAS A MASS OF 0.025 g, AND A DENSITY OF 0.007 g/mL? Knowns/UnknownEquationShow workAnswer/units V=M/D M=0.025 g D=0.007 g/ml V=? V=0.025 g/ 0.007 g/ml V=3.6 ml