Science

1
Chapter 1
Science Skills
2
Objectives

• Explain the history of science
• List the major branches of natural science and
  describe how they overlap
• Describe the relationship between science and
  technology

3
About Science

• Science is the process of discovering and
  explaining the order of nature and how its parts
  connect to one another
• Predates recorded history
• _________ ________ is the premise of science
• - Gained headway in Greece in the 3rd, 4th
  centuries B.C
• - Halted in Europe due to ___________ ________
• - __________ Polynesians continued charting the
  stars, and planets

4
About Science Cont.

• - Arab nations developed ___________
• - Reintroduced by ______________
• - Universities emerged in the _____ century
• - 15th century allowed
• - 16th century controversy

5
Science Technology

• Scientist who do experiments to learn more about
  the world are practicing _____ ________, also
  defined as the continuing search for scientific
  knowledge
• Applying knowledge to practical problems is
  called __________
• Science and technology are ____________.
• - advances in one leads to advances in another
• ex.

6
Branches of Science

• Natural Science
• Tries to understand nature, which really means,
  the whole universe
• Usually divided into 3 sub categories
• Life science Biology, Zoology, _________
• Physical science Chemistry, ___________
• Earth science geology,
• Today these classifications overlap
• - Biophysics -
• - _________

7
Objectives

• Describe the steps in a scientific method
• Compare and contrast facts, scientific theories,
  and scientific laws
• Explain the importance of models in science, and
  their use to investigate nature

8
The Nature of Science

• Scientists believe that the universe can be
  described by basic ________, and these rules can
  be described by careful, methodical study, also
  known as the _________ __________
• Investigation
• Experimentation
• Observation

9
Critical Thinking

• Applying logic and reason to observations and
  conclusions
• ex. If you are doing you homework and the lights
  go out, what do you do?
• -
• -
• -
• A person who thinks like a scientists would first
  ask questions and then make observations

10
Scientific Method

• Developed by Francis Bacon __________
• Formal method for conducting science
• Based on critical thinking and ___________
• Series of logical steps to follow in order to
  solve problems

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Scientific Method Cont.

1. Recognize the problem and propose a question
2. Form a ____________
3. _______ hypothesis
4. _____________ ______________
5. Formulating a conclusion based on experimental
   findings

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Observations

• Observations
• - use our _________ to gather information about
  the world around us
• - ____ types of observations.

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Qualitative Observations

• Qualitative observation (quality)
• - usually made with our senses
• ex.
• ex.

15
Quantitative

• Quantitative observation (___________)
• - how many (will be a number)
• - based on _______ _________________.
• ex.

16
Recognizing the problem

• Your on your way to a friends house and your car
  suddenly stops.
• Problem
• Observations
• Qualitative
• Quantitative

17
Inferences

• Inference
• - a logical interpretation of an event that is
  based on observations and prior knowledge.
• ex.
• - could be in trouble (ISS, OSS, expelled)
• -
• - student not feeling well
• -

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Inference or Observation?

• The dog is wagging his tail. ___
• The dog is happy. ____
• The liquid is green with white bubbles in it.
  ____
• The liquid is probably bad for you. ___
• The cafeteria ladies dont like kids. ____
• The cafeteria ladies are frowning. ____

19
Hypothesis

• A tentative statement that proposes a possible
  ___________ to some phenomenon or event
• ex.
• A controlled experiment is an experiment in which
  only one __________, is changed at a time
• Variables anything that can ___________ in an
  experiment
• ___________ /Dependent
• Manipulated /___________

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Hypothesis Cont.

• UV light may cause skin cancer
• Independent Variable
• - variable that is _____________ by the
  scientist
• ex.
• Dependent Variable
• - observed, ____________ due to changes in the
  independent variable
• ex.
• Controlled Variables
• - variable that remain _____________
• ex.

21
Hypothesis Cont.

• Formal
• - written as an if, and, then statement
• - If
• - And (not always
  included)
• - Then
• ex.

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Predicting the Consequences

• If the hypothesis is correct
• If the hypothesis is incorrect

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Hypothesis Cont.

• Theory
• - a well-tested explanation for a set of
  _____________ or experimental results
• - never proved, may become stronger or may
  become obsolete in time
• ex.
• Law
• statement that summarizes a ________ found in
  nature
• does not attempt to explain it
• verified over and over again
• ex.

24
Performing Experiments

• Must have a ___________ _________
• Record all data
• Repeat experiment several times until findings
  are conclusive
• Why?

25
Formulating a Conclusion

• Written paragraph on the outcome of your
  experiments
• Key concepts
• Hypothesis, correct or incorrect
• Use of Data to support or discredit hypothesis
• Errors

26
Models

• Scientific models are ______________ of an object
  or event that can be studied to understand the
  real object or event
• - make it easier to understand things that
  might be too difficult to observe directly
• - ____________
• Computer
• Mathematical
• in a state of constant change, new models
  replace old

27
Objectives

• Explain the objective of a consistent system of
  units, and identify the SI units for length, mass
  and time
• Identify what each common SI prefix represents
• Demonstrate measurement of objects
• Be able to convert measurements

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Units of Measurement

• Mathematics is the language of science
• International System of Units (SI)
• started with the metric system in France in 1791,
  and is now a revised version
• uses ____ SI units length, ________,
  temperature, time
• based on units of ______
• ex.

29
Units of Measurement Cont.
Gig G Billion 1,000,000,000
Mega Million 1,000,000
k 1,000
h Hundred
Deka Ten
m,l,g One 1
d Tenth 1/10
Centi c Hundredth
Milli Thousandth 1/1000
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Conversions

• 4 Steps
• List the given and unknown values
• - given
• - unknown
• Determine the relationship between units
• Write the equation for the conversion
• Insert the known values into to equation, and
  solve

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Conversions Cont.

• SI units
• Smaller to larger
• - remember it takes _____ of a small unit to
  make a larger unit
• - multiply the units to get a larger number
• ex.
• Larger to smaller
• - it takes less of a larger unit to make a
  smaller unit
• - divided the units to get a smaller number
• ex.

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Conversion Problems

1. Convert 1.6 kilograms to grams
2. Convert 2500 milligrams to kilograms
3. Convert 50 centimeters to decameters

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Making Measurements

• - many observations rely on ___________
  measurements
• - most basic measurements generally answer
  questions such as how much time did it take and
  how big
• - common measurements are ____, length, mass,
  _______ and weight

34
Length

• The straight-line distance between any two points
• SI unit
• - __________
• Tools
• - Tape measure, ruler

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Volume

• Amount of space any object occupies
• SI unit
• _________ ________ Very big, so we use..
• Liter
• Tools
• -
• -

36
Mass

• Measure of the quantity of __________ in an
  object
• SI unit
• - _______
• Tools
• __________
• __________
• __________

37
Weight

• The ___________ force exerted on an object by the
  nearest most massive body (Earth)
• SI unit
• - ____________
• Tools
• ____________
• ____________

38
Objectives

• Understand the difference between precision and
  accuracy
• Use scientific notation and significant figures
  in problem solving
• Interpret line graphs, bar graphs, and pie graphs

39
Scientific Notation

• - also referred to as__________ ___________
• used to express numbers that are very very large
  or very very small
• way to write numbers concisely
• used in a computation with far greater ease
• used in scientific fields

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Scientific Notation Cont.

• General format
• N x 10
• N any number (except 0)
• X exponent of 10
• Two Components
• - __________ 2.16 x 102
• Exponent 2.16 x 102

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Scientific Notation Cont.

• Examples
• 101 10 x 1 10
• 102 10 x 10 100
• 103 10 x 10 x 10 1000

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Scientific Notation Cont.

• Numbers that are greater than 10
• Locate the decimal, move it so there is only one
  non-zero number to its ______
• Resulting placement of the decimal will produce N
• ________ the number of places that you had to
  move the decimal
• Multiply the two parts together, number of
  positions will equal x
• ex.

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Scientific Notation Cont.

• Numbers less than 10
• Locate the decimal, move it so that there is only
  one non-zero decimal to its left
• The resulting placement of the decimal will
  produce N
• Count the number of places that you had to move
  the decimal
• Multiple the two parts together, the number of
  positions will equal ____
• ex.

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Scientific Notation Problems

• Problems
• 800 000 000 m
• 0.0015 kg
• 60 200 L
• 4.5 x 103 g
• 6.05 x 10-3 m
• 1.99 x 10-8 cm

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Scientific Notation (,-)

• Addition and Subtraction
• exponents must be the _____ in order to calculate
• If they are the same ______ the decimal part
  (numbers) use the _________ exponent (10x)
• ex.
• if they are different move the decimal until they
  ___________ are the same, then solve
• ex.

46
Scientific Notation (,-) Problems

• 6.7 x 1012 7.8 x 1012
• 3.7 x 108 2.1 x 105
• 7.25 x 105 - 2.2 x 105
• 1.4 x 106 - 3.9 x 10-2

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Scientific Notation Cont.

• Multiplying
• ______ the powers of 10
• ex.
• Dividing
• _________ the powers of 10
• ex.

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Scientific Notation Problems (x,/)

• Multiplying
• (3.1 x 102 cm) x (1.22 x 104 cm)
• (2.99 x 105 km) x (6.88 x 102 km)
• Dividing
• (5.75 x 10-5 m) / (9.9 x 10-2 m)
• (7.83 x 104 km) / (3 s)

49
Significant Figures

• Significant Figures
• - all the digits that are known in a
  measurement, plus the last digit that is
  estimated
• Necessary rules to ensure accuracy of measurement
• A digit is significant if, and only if
• a. It is a ___________ digit.
• b. It is a zero that lies between two
  ____________ _________
• c. It is a zero that is both RIGHT of the
  decimal and RIGHT of any other
  significant figure, regardless of the
  distance between them.

50
Significant Figures Cont.

• When considering significant figures, we never
  use the following for rounding, nor do we count
  their significant figures
• a.________ numbers. There is no uncertainty
  in a (reasonably small) count, e.g. 15
  pennies in a jar.
• b.defined numbers. There is no uncertainty
  in 60 minutes 1 hour.
• ex.
• - use the _______ amount of digits used in the
  problem
• - make sure to ________, if needed, only after
  _____ the calculations have been done

51
Rules for Making Calculations with Significant
Figures

• Addition and Subtraction
• - answer must be rounded so that it contains the
  _____ number of digits to the _______ of the
  decimal point as there are in the measurement
  with the __________ number of digits to the right
  of the decimal point
• ex.
• Multiplication and Division
• - the product or quotient should be rounded off
  to the same number of significant figures as in
  the measurement with the _________ significant
  figures
• ex.

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Limits of Measurements

• Precision
• - is a gauge of how exact a measurement is
• ex.
• Accuracy
• - is the closeness of a measurement to the
  actual value of what is being measured
• ex.

53
Presenting Scientific Data

• Line Graphs
• Used to show continuous changes
• Consist of an x axis (independent), and a y axis
  (dependent)
• Bar Graphs
• - Used to ____________ data for several
  individual items or events
• Pie Charts
• - Used to display data that are __________ of a
  _________

54
Objectives

• Relate the Celsius, Kelvin, and Fahrenheit
  temperature scales
• Be able to identify the boiling and melting
  points of each scale.
• Understand how to convert between scales

55
Temperature Energy

• Methods of measuring temperature
• - __________
• - thermometers
• 3 Scales
• - _____________ (__)
• - _____________ (0C)
• - Kelvin (K)
• Measuring temperature
• - physical property of substances
• - most objects __________ when their temperature
  increases (principle of thermometers)

56
Fahrenheit

• Used primarily in the US
• - _____________
• - cookbooks
• Scale
• - water freezes at _______
• - boils at _______

57
Celsius

• Used in most other countries
• - Other countries such as Canada
• Scale
• - water freezes at ______
• - boils at _______
• almost twice as large as a degree Fahrenheit

58
Kelvin

• Used primarily in ___________, SI unit
• Scale
• - ______________ _______
• - temperature at which an objects energy is
  minimal (lowest possible temperature)
• - ___________
• - unit of Kelvin is equal to a degree on the
  Celsius scale

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Conversion Between Scales

• Celsius to Fahrenheit
• Fahrenheit
• - F
• Problems
• a. boiling point of hydrogen -252.870C
• b. normal body temperature 370C
• c. room temperature 22.20C

60
Conversion Between Scales

• Fahrenheit to Celsius
• Celsius
• C Problems
• a. summer day in Phoenix 1100F
• b. temperature of dry ice 69.70F
• c. highest recorder temperature on Earth 1360F

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Conversion Between Scales

• Fahrenheit to Kelvin's
• - 1st convert Fahrenheit to Celsius
• - 2nd Celsius to ___________
• Equations
• 0C (5/9(0F - 32.00))
• K ___________________

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Fahrenheit To Kelvin's Conversions

• Fahrenheit to Kelvin's
• K (5/9(0F - 32.00) 273)
• Problems
• a. liquid nitrogen 279.40F
• b. coldest temperature recorded
• 128.60F
• c. dry ice -69.70F

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Celsius to Kelvin's Conversions

• Celsius to Kelvin's
• K C 273
• Problems
• a. liquid hydrogen -269.00C
• b. melting point of gold 10640C
• c. normal temperature of the North Pole -40.00C