1. Bell work 35-2
Explain why it is important for scientists to do multiple trials (repetition) during an experiment
If you have not given me your t-shirt size for MHS shirts, see me ASAP!

2. FSSA Nature of Science Notes Complete/Check practice tests
Today’s Agenda
FSSA Nature of Science Notes
Complete/Check practice tests

3. FSSA Review – Scientific Thinking and problem solving

4. QUIZ Thursday! FCAT Science covers the following topics
Nature of Science
Life Science
Earth/Space Science
Physical Science
Use FCAT explorer

5. Identify The variable that the experimenter physically manipulates
Independent Variable – the thing that the experimenter changes
Trick to remember – pretend that you are doing the experiment
Independent variable is what I change
Some Examples of things that can be changed in an experiment
Amount of….
Type of….
Species of ….
Shape of….
Size of….
Weight/Mass of

6. How many independent variables should be manipulated at once?
ONLY 1….
Ever
Ever!!!!!!!!

7. What is the variable that you measure as a result of changing the IV?
Dependent variable
Trick to remember
The dependent variable depends on what you do to the independent variable

8. What are the factors you keep the same in an experiment?
Constants
They are sometimes referred to as the “controlled variables” because they are controlled. Don’t confuse with the control group

9. What is the group in which you do not apply the independent variable?
The control group
If you are analyzing results and there is no control group, the results are most likely not valid…. In other words you can’t draw a conclusion!

10. What is a hypothesis based on?
Background research or initial observations

11. Besides an If/then statement What should a strong hypothesis include?
Independent and dependent variables… the more specific the better
Example: If the nitrogen content of soil is increased by 20%, then the growth of the plant will increase by 5%.

12. What do you do if your hypothesis is not supported by data
Modify the hypothesis and experiment again

13. Hypotheses
Kathryn wants to keep squirrels from eating the bird feed she puts out for the birds in her yard. She decides to conduct an experiment to see which types of feed the squirrels seem to prefer. Based on her observations, she hypothesizes that the squirrels prefer when berries are in the feed.
Why was it important for Kathryn to generate a hypothesis prior to starting her experiment?
SC.8.N.1.4

14. Does scientific understanding change or stay the same?
A basic truth in Science…..
Scientific ideas, understanding, and explanations change as technology improves and we make new discoveries
Examples to know:
Solar system models (helio-, geo- centric)
Atomic theory
Cell theory
Continental drift – plate tectonics

15. Using Technology
All allow scientists to see things they could not normally see, sub and shuttle allow people to go TO the places they want to see while the telescope and microscope allow vision in controlled environment.
Explain how the pairs of technologies in the images above are used in science. In this respect, how are two pairs different and how are they similar?
SC.8.E.5.10

16. To what change in scientific knowledge does the cartoon above refer?
SC.6.N.2.2(SC.8.N.1.5), SC.7.N.2.1(SC.7.N.1.7)

17. Explanations based on Evidence
The Theory of Plate tectonics describes how the Earth’s crust moves and has been moving over time creating the surface as we know it today.
What evidence could be/has been used to support this theory? How could we/do we model this theory?
SC.8.N.1.6 (SC.7.N.1.6)

18. Why do scientists conduct multiple trials?
Multiple Trials aka Repetition (because you repeat your experiments) are done to validate the data.
Without conducting multiple trials, data – and conclusions drawn from it – are not reliable

19. How do scientists validate each other’s work
By replication – scientists repeat research in order to ensure it is reliable

20. Replication vs Repetition
Elizabeth conducted an experiment to determine the which toy car would travel the fastest down a ramp. She sent three different toy cars down a ramp five times each and recorded the time it took for the car to reach the bottom of the ramp. Elizabeth reported to her class that the smallest car had the greatest speed. After hearing Elizabeth’s results, her classmate Kelley wanted to conduct the same experiment because she felt the results might be inaccurate. Kelley followed Elizabeth’s exact procedures to conduct her own experiment.
Which underlined sentence above is an example of replication and which is an example of repetition? Why are both activities important for science experimentation?
SC.7.N.1.2, SC.6.N.1.2, SC.8.N.1.2

21. How is empirical evidence related to a theory?
Empirical evidence is the collection of results from scientific investigations from many scientists
Used to support a theory
The more empirical evidence, the stronger the theory…. Like the legs of a table

22. Modifying Theories
Three of the many models of the atom are shown above. Describe some of the ways that the Atomic Theory has changed over time.
SC.8.N.3.2

23. How can you get more precise data?
Use measuring instruments that have more specific measurements (farthest place value to the right)
The more precise, the more reliable
2.435
2.4 2

24. Comparing Investigations
Two students conducted the same experiment measuring pH. Sarah used a digital pH meter. Olivia used pH paper. They recorded their results in the tables below.
Liquid pH
Lemon Juice 2
Water 7
Coffee 5
Bleach 13
Liquid pH
Lemon Juice
1.9
Water
7.3
Coffee
5.5
Bleach
12.8
Which table represents the data from which student? Explain your choices
SC.6.N.1.4

25. Which variable is always placed on the x axis of a graph?
Independent variable (the thing that was changed)
Tricks to remember
Think of the y-axis as a flag pole and think of the x-axis as the ground. The ground can be independent, but you can't stand the flag up without land. So the flag pole depends on the land. y depends on x.
Y to the Sky, X to the left

26. Variables
Lindsey wanted to determine how the temperature of the water in her pool changed throughout the year. She took measurements and made the following graph.
In her investigation, what was the test (dependent) variable and what was the outcome (independent)variable?
SC.7.N.1.4

27. What is the difference between a theory and a law?
A theory explains
A law describes

28. Plate Tectonics Gravity Conservation of Energy Evolution
Theories vs Laws
Plate Tectonics
Gravity
Conservation
of Energy
Evolution
Which topics above relate to a theory and which to a law? How do theories and laws differ?
SC.7.N.3.1 (SC.6.N.3.1)

29. Can a theory ever turn into a law?
NO…. NEVER, EVER, EVER, EVER!!!!

30. Can we prove anything with experiments?
NO…. Nothing is ever completely proven… only supported.

31. Evidence, Data, and Conclusions
Motion of objects traveling down a ramp
Mass (g)
Trial 1
Time (s)
Trial 2
Trial 3
Car A
15.5
4.7
4.9
Car B
20.2
3.3
2.0
3.1
Car C
7.9
5.9
5.6
5.8
Ball A
15.7
4.8
4.6
Ball B
27.1
5.3
5.0
Ball C
5.5
6.0
6.2
6.3
Based solely on the data above, what is one conclusion you can make? What evidence do you have to support it? What other evidence would you like to have?
SC.8.N.1.1, SC.8.N.1.3,
SC.6.N.1.1, SC.7.N.1.1

32. Are all investigations based on experiments?
No… some are based on surveys, observations, and research (descriptive)

33. Experiment vs Investigation
Melanie and Brody want to find out whether wooden bats or metal bats allow baseballs to travel farther.
Melanie asks five different people to hit ten balls with each type of bat and she measures the distance each ball travels.
Brody researches the physical properties of the pine wood and the aluminum metal and then estimates the possible distance a ball could travel with a given force.
Which student conducted an experiment and which student conducted an investigation? Explain your answer.
SC.7.N.1.3, SC.6.N.1.3

34. What is the purpose of a model in science?
To show concepts that are difficult to show in their natural form… things that are too fast, too slow, too small, too large etc.
Trick for FCAT – find what the model CAN’T SHOW

35. Using Models
Books often have images like the one above for our solar system. How might this type of image be helpful and how might it be misleading?
SC.7.N.3.2