1. Physical Science Ch. 1 “Introduction To Science”
Ch. 1 Section 1 Notes
“The Nature of Science”

2. How Science Takes Place
Turn to page 5
A scientist may perform experiments to find a new aspect of the natural world, to explain a known phenomenon, to check the results of other experiments, or to test the predictions of current theories.

3. How science takes place
Scientists answer questions by investigating.
Scientists plan experiments
Scientists observe
Scientists always confirm results.

4. Wilhelm Roentgen
Found that the cathode rays passed through almost everything, but dense materials absorbed some of the rays.
He published his findings and called them X rays. (x represents an unknown in a mathematical equation.)
3 months later, another doctor used his discovery to set the bones in a boy’s arm.
In 1901, Roentgen received the first Nobel Prize in physics for his discovery.

5. The Branches of Science
Science is observing, studying, and experimenting to find the nature of things.

6. Science can be broken down into two main categories:
Social science (deals with individual and group human behavior)
Natural science (tries to understand how “nature,” or “the whole universe” behaves.
Most of the time, natural science is divided into biological science, physical science, and Earth science.
Look at Figure 3 on page 7

7. The branches of science work together
Science and technology work together. -Technology is the application of science for practical uses.

8. Scientific Laws and Theories
Theories explain why something happens, and laws describe how something works.
A scientific law describes a process in nature that can be tested by repeated experiments. A law allows predictions to be made about how a system will behave under a wide range of conditions.
It does NOT explain how a process takes place.

9. Theory
A theory gives an explanation of how a natural process works

10. To be valid, a theory must pass several tests:
A theory must explain observations clearly and consistently.
Experiments that illustrate the theory must be repeatable.
You must be able to predict the results from the theory.

11. Mathematics can describe physical events
Qualitative vs. Quantitative
Universal gravitation equation:
F=G m(1) x m(2) / d x d

12. Models Computer models Water molecule models Atom molecule models Etc.
Meteorologists use it to help forecast the weather.
Water molecule models
Atom molecule models
Etc.

13. 1.1 Homework
1.1 Concept Review
1.1 Review page 12 #s 1-3, 5 & 6

14. Ch. 1 Section 2 Notes
Turn to page 14
The Way Science Works

15. Science Skills
Identifying problems, planning experiments, recording observations, and correctly reporting data are some of the most important science skills.
The most important skill is learning to think creatively and critically.

16. Critical thinking helps you solve problems logically.
If you approach a problem by asking questions, making observations, and using logic, you are using critical thinking.
How much is the big bag?
How much is the small bag?
How many ounces are in each?
Etc.

17. A. Science Skills
Critical thinking—applying logic and reason; objective; consider all factors; analyze
2. Using the scientific method—series of logical steps to solve problems
a. ask questions, gather info, form hypothesis

18. Scientists use scientific methods to solve problems.
Scientific methods are general ways to help organize your thinking about questions.
Scientific methods are sets of procedures that scientists use, but the steps may vary
Look at Figure 2 Pg. 15
Most scientific questions begin with observation. Then, they are usually followed by a hypothesis.
QUESTION:
Do you have to use exactly the same steps every time that you use a scientific method?

19. Scientists test hypotheses.
A hypothesis is tested by doing a controlled experiment.
In a controlled experiment:
Variables that can affect the outcome of the experiment are kept constant, or controlled, except for the one that you want to measure.
Only the results of changing the given variables are observed.
It is best to only change one thing at a time to test the hypothesis. This will make it easier to reach your conclusion.

20. 3. test hypothesis
a. a good experiment tests only one variable at a time
i. if more than one were tested, you wouldn’t know which one caused the change
b. variable—anything that can change

21. Experiments test ideas.
4. Conducting experiments
a. no experiment is a failure
b. scientists use results to revise hypothesis and plan new experiments
c. always keep question being tested in mind
d. sometimes scientists must make observations and use models instead of experiments

22. 5. Using scientific tools
a. Observation
i. Senses
ii. Microscopes
iii. Telescopes
iv. Spectrophotometers
v. Particle accelerators

23. B. Units of Measurement
SI—Systeme Internationale
1. SI units are used for consistency
a. based on metric system
b. 7 base units
2. SI prefixes are added for very large or small numbers

24. Basic units in SI and metric
Length—meter—m
Mass—gram—g
Time—second—s
Temp—Kelvin—K
Current—ampere—A
Substance—mole—mol
Lumination—candela—cd

25. SI and metric prefixes Giga- G 109 1 000 000 000 Mega- M 106 1 000 000
kilo- k
103
1000
hecto- h
102
100
deka- da 10
Basic unit
(m, l, g) 1

26. SI and metric prefixes deci- d 10-1 0.1 centi- c 10-2 0.01 milli- m
10-3
0.001
micro-
u (mu)
10-6
nano- n
10-9
pico- p
10-12

27. 3. Making measurements (pp. 18-19)
i. length—distance between 2 points
unit: use:
ii. mass—quantity of matter

28. iii. volume—space; capacity
unit: use:
iv. weight—force of gravity on object;
not really used in SI
unit: use:

29. 1.2 Homework
1.2 Concept Review
1.2 Review page 21 #s 1-5, 9 & 10

30. Ch. 1 Section 3 Notes
Turn to page 22
Organizing Data

31. 1.3 Organizing Data
A. Presenting scientific data
1. line graph—shows continuous changes

32. 2. bar graph—compares items

33. 3. pie graph—shows parts of a whole

34. B. Scientific Notation—a simple number x a power of ten
1. the exponent (power) tells how many places to move decimal
2. positive—move right; negative—move left

35. 4 x 107 =

36. 3.7 x 10-8 =

37. 6.23 x 109 =

38. 3.04 x 10-6 =

39. 300,000,000,000 =

40. =

41. 652,070,000,000,000 =

42. =

43. C. Significant figures—the digits in a. measurement that are known
C. Significant figures—the digits in a measurement that are known with certainty
How many significant figures?
1.58 ____
2.0 ___
7000 ___
2.09 ___
60830 ___

44. 1. precision—how close measurements are to each other
-the degree of exactness
-smaller measurements are more precise

45. 2. accuracy—how close a measurement is to the true value

46. 1.3 Homework
1.3 Concept Review
1.3 Review #s 1-7 page 28