go to section chapter 1 science skills. go to section section 1.1 what is science?

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Chapter 1

Science Skills

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Section 1.1

What is Science?

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Science From Curiosity

• “Necessity is the mother of invention”

– Fire, tools, language, etc.

• Science- system of knowledge and the methods used to find that knowledge

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• Science begins with curiosity and ends with discovery.

• Observations

– Quantitative- numerical

• 27°, 36.7 grams, etc.

– Qualitative- descriptive

• Blue liquid, gas given off, etc.

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Science and Technology

• Technology- the use of knowledge to solve practical problems

– Telephone, cell phone, TV, medicine, etc.

• Science and Technology are interdependent. Advances in one lead to advances in the other.

– Physics transistor radios, computers, space science

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Branches of Science Figure 3

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The Big Ideas of Physical Science

• Describes the basic “rules” of nature.

• Four major areas

• Space and Time

– Universe is very old and very big

– Universe is 13,700,000,000 years old

– Universe is 700,000,000,000,000,000,000,000,000 meters in diameter

• Matter and Change

– Small amount of universe is matter

– Matter has volume and mass

– Matter made of building blocks called atoms

– Atoms made of smaller blocks called protons, neutrons, and electrons

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Big Ideas, con’t

• Forces and Motion

– Force causes changes in motion

– World filled with motion and forces

• Energy

– Energy exists in many forms

– Moving objects have kinetic energy, nonmoving have potential energy

– Matter has energy, can be changed into other forms

– Energy can be transferred from one form or object to another, never destroyed

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Section 1.2

Using A Scientific Approach

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Scientific Methods

• Scientific Method- organized plan for gathering, organizing, and communicating information

• Goal- to solve a problem or better understand an observed event

• Observation- information obtained through the senses

• Hypothesis- proposed answer to a question

– Manipulated variable- causes a change in another

– Responding variable- variable that changes in response

– Controlled experiment- one variable deliberately changed at a time

• Scientific Theory- well-tested explanation for a set of observations or experimental results

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A Scientific Method Figure 7

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Scientific Laws

• Scientific Law- statement that summarizes a pattern found in nature

– Describes an observed pattern in nature without attempting to explain it (explanation provided by theory)

– Generally verified over and over

– Newton’s Laws of Motion, etc.

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Scientific Models

• Model- representation of object or event

• Scientific models make it easier to understand things that might be too difficult to observe directly

– Globe

– Atomic models

– Buildings

– Prototypes of cars

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Working Safely in Science

***Use safe procedures when carrying out investigations.

***Follow your teacher’s instructions carefully.

***Know all safety rules and procedures that have been introduced by your teacher.

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Interest Grabber

Measuring Length by the HandfulThe English units that we use in the United States developed over a long period of time. For example, the hand was devised in ancient times as a unit of length. It was defined as the length of a

person’s hand from the little finger to the thumb. Today the height of horses is still measured in hands, but the definition of a hand is standardized at 4 inches or 10.16 centimeters.

1. Why did the hand produce unreliablemeasurements before it wasstandardized?

2. Measure the height of your desk in hands. Compare your results with other classmates. How do the results vary?

Section 1.3

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Section 1.3

Measurement

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Using Scientific Notation

• Scientific notation- way of expressing very large or very small numbers

– Makes them easy to work with

– Expressed as a number between one and ten multiplied by a power of ten

– Exponent can be a positive number (large number) or a negative number (less than one)

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Converting Numbers into Scientific Notation

• Large numbers:

– Put a decimal point after the first number and drop the zeroes

– Count the number of places from the decimal point to the end of the number (including zeroes)- this is your exponent

– Ex. 123,000,000,000 would be 1.23 x 1011

• Small numbers:

– Put a decimal point after the first whole number and drop the zeroes

– Count the number of places from the decimal point backward to the original decimal point (including zeroes)- this is your NEGATIVE exponent

– Ex. 0.0000013 would be 1.3 x 10-6

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Write each in standard notation:

• 6.52 x 103

• 4.6322 x 104

• 8.66185 x 104

• 8.71 x 104

• 7.0 x 10-5

• 3.65 x 10-6

• 2.17 x 10-2

• 3.34 x 100

• 6520

• 46322

• 86618.5

• 87100

• 0.00007

• 0.00000365

• 0.0217

• 3.34

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Write each in scientific notation:

• 0.07882

• 0.00000272338

• 118000

• 87200

• 0.00002786

• 0.000000664

• 450

• 74171.7

• 770

• 0.0000085

• 7.882 x 10-2

• 2.72338 x 10-6

• 1.18 x 105

• 8.72 x 104

• 2.786 x 10-5

• 6.64 x 10-7

• 4.5 x 102

• 7.41717 x 104

• 7.7 x 102

• 8.5 x 10-6

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Using Scientific Notation

Section 1.3

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Complete the following:

• (3.76 x 104) + (5.5 x 102)

• (4.8 x 105) - (9.7 x 104)

• (7.25 x 103) x (3.2 x 102)

• 5.5 x 103 / 1.1 x 102

• change 5.5 x 102 to 0.055 x104 3.76 + 0.055 = 3.815 x 104

• change 9.7 x 104 to 0.97 x 105 4.8 - 0.97 = 3.83 x 105

• 7.25 x 3.2 = 23.2 and 10 3+2 = 105

2.32 x 106

• 5.5/1.1 = 5.0 and 10 3-2 = 101

5.0 x 101

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SI Units of Measurements

• International System of Units (Systeme International de Unites)

– Revised metric system (1791 in France)

• Base Units

– Seven units system is based on

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SI Units con’t

• Derived Units- made by combining base units

– Density (g/cm3), Area (m2), Volume (m3), Pressure (kg/m·s2), Energy (kg·m2/s2)

• Metric Prefixes

– Prefixes put in front of a unit to make it stand for larger or smaller units

• Conversions

– Using a ratio to switch from one unit to another

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A List of the Metric Prefixes

Multiplier

Prefix Symbol Numerical Exponential

giga G 1,000,000,000 109

mega M 1,000,000 106

kilo k 1,000 103

hecto h 100 102

deca da 10 101

no prefix means: 1 100

deci d 0.1 10¯1

centi c 0.01 10¯2

milli m 0.001 10¯3

micro 0.000001 10¯6

nano n 0.000000001 10¯9

pico p 0.000000000001 10¯12

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Limits of Measurement

• Precision- how exact a measurement is

– Limited by least precise measurement used in a calculation

• Accuracy- how close a value is to the accepted

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Measuring Temperature

• Thermometer- measures temperature• Scales:

– Celsius (°C) scale

– kelvin (K) temperature scale.

• kelvins, NOT degrees kelvin,

• not capitalized,

• symbol (capital K) stands alone with no degree symbol.

– Fahrenheit (°F) non-metric temperature scale

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Significant Figures

• Shows the precision of a measured value

• Rules:– 1. Non-zero digits are always significant.

– 2. Any zeros between two significant digits are significant.

– 3. A final zero or trailing zeros in the decimal portion ONLY are significant.

– How many significant figures are in the following;

• 5.40

• 210

• 1000

• 1000.

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Interest Grabber

Creating and Interpreting GraphsMany people have pets. One survey of pet owners showed the following breakdown of the type of pets owned: 35% dogs; 35% cats; 10% birds; 5% hamsters, gerbils, mice, rats; 5% reptiles; and 10% other.

1. Copy the incomplete circle graph below on your paper. Complete the graph using the survey data. Estimate the

angle of each section of your completed circle graph. Give your graph a title and label what each section of the graph represents.

2. Explain how viewing the graph conveys information to the reader more quickly than reading the list of data.

Section 1.4

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Section 1.4

Presenting Scientific Data

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Organizing Data

• Data Tables

– Two variables- manipulated and responding

• Line Graphs

– Shows changes in related variables

– Slope-ratio of changes (rise/run)

– May be direct proportion (two are constant) or inverse proportion (product of two is a constant)

• Bar Graph

– Compare sets of measurements

• Circle Graph

– Relate part to whole

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Data Table

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Line Graph

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Bar Graph

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Circle Graph

Per Capita US Consumption of Milk, 1975-95

Graph A

Graph B

Graph C

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Communicating Data

• Communication is essential!

– Scientific Journals

– Speaking at Conferences

– Conversations

– E-mail

– Web sites

• Peer review

– Scientists review each others’ work

– Comments, suggestions, criticism, find errors

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Scientific Notation WS

• 7.882 x 10 -2

• 2.72338 x 10 -6

• 1.18 x 10 5

• 8.72 x 10 4

• 2.786 x 10 -5

• 6.64 x 10 -7

• 4.5 x 10 2

• 7.41717 x 10 4

• 7.7 x 10 2

• 8.5 x 10 -6

• 0.0000003443

• 0.000000775763

• 0.00000058

• 1525000

• 65815700

• 0.00051821

• 0.000000121

• 0.00000052314

• 0.00007141

• 5256000