INTRODUCTION TO SCIENCE

CHAPTER 1

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WHAT IS SCIENCE?

• Science is the study of…

• Everything!!

• A way of learning about the natural world.

• Scientist: a person who

studies, or has expert

knowledge of a natural or

physical science 2

PHYSICAL SCIENCE

• Physical Science: The study of matter

and energy

• Matter: the stuff the universe is made of

• Energy: ability to do work

• Two major classes of physical science

• Chemistry: the study of interactions of

matter

• Physics: the study of motion and energy

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THEORIES & LAWS

• Law: describes a process in nature that can be tested by

repeated experiments

• Based on facts and have been proven, If not supported by new

information, the law is rejected

• Law of Conservation of Energy

• Theory: attempts to explain why these processes and

observations are so.

• Based on observations and can be tested, If new information if

discovered, the theory is changed

• Theory of Evolution

• BOTH SUPPORTED BY EVIDENCE

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MODELS & TECHNOLOGY

• Model: any representation of an object or a system

• Technology: the application of science for

practical purposes

• We are surrounded by this daily!

• Cathode Rays, CT Scans

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SCIENTIFIC METHOD

• Method of organizing information and solving problems

1. Make an observation (use your 5 senses)

2. Ask a question

3. Research

4. Form a hypothesis (predict an outcome)

5. Experiment (test the hypothesis)

6. Analyze your results (record and organize your data)

7. Draw conclusion (was your prediction correct?)

8. Repeat your work and share it with others 6

SCIENTIFIC METHOD • Observation: I can’t wake up for school

• Question: How can I get up on time?

• Research: Go to bed earlier, set alarms, less technology before bed

• Hypothesis: If I go to bed earlier, then I will be able to wake up.

• Experiment: Try to go to bed earlier, and record if you get up earlier

• Analyze your results: Did it work each day?

• Draw conclusion: Did you confirm or disprove your

hypothesis?

• Repeat & Share: Always double check, tell someone about your

discovery

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EXPERIMENT • Experiment: a controlled procedure carried out to test

a hypothesis

• Variable: condition or trait you are testing (or changing) • Independent variable: this variable is manipulated by the

experimenter, DOES NOT change in response to other variables

• Dependent variable: the variable that changes in response to the independent variable, or being measured

• Only ONE variable is tested in an experiment!! 8

EXPERIMENT

• Control group: does not receive the variable

• Experimental group: exposed to the independent variable, then compared to the control group

• NO EXPERIMENT IS A FAILURE! • The results may help you discover

something new even if they weren’t the results you wanted

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DATA

• Qualitative: data that cannot be

measured, it describes a

QUALITY

• The softness of a cat’s fur, the color

of the sky

• Quantitative: data involving

number, it shows a QUANTITY

• The age of your car, the hairs on

your head

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LAB SAFETY

• Failure to follow lab

safety rules will result

in disciplinary

consequences!

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EQUIPMENT

• Metric Ruler: measures distance in centimeters, each line in between represents a millimeter (one tenth of a centimeter)

• Graduated Cylinder: measures volume in milliliters

• Meniscus: lowest point of the curve, read from here by putting your head at the same level

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MEASUREMENT

• Math is the language of science

• Scientists use the SI system

(Systeme International d’Unites)

because it is consistent

• The SI system is based on the

metric system and has BASE

UNITS of measurement 13

METRIC SYSTEM

• Measurements are made in specific units called BASE UNITS

• Length: distance

• Base Unit: meter (m)

• Volume: amount of space something takes up

• Base Unit: liter (L) for liquids, centimeters cubed (cm3) for solids

• Mass: amount of matter in an object (not the same as weight)

• Base Unit: gram (g)

• Time: the amount of time something takes

• Base Unit: second (s)

• Temperature: how hot or cold something is

• Base Unit: Celsius (°C) or Kelvin (K)

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METRIC SYSTEM

• Some measurements are too large or small to be measured in meters,

liters, or grams so we add prefixes to them in order to avoid decimals and

a lot of zeroes

• Prefix: something added to the front of a word to change its meaning

• Metric prefixes represent multiples of ten

• Add the prefix symbol to the base unit symbol when writing a unit of

measurement

kilo meter

k m 15

METRIC SYSTEM

km = 1,000 meters 16

CONVERSIONS

• Converting from one metric unit to the other

• Write down - G’’ M’’ k H Da base d c m

• Put your pencil on the given unit (km)

• Move the necessary number of spaces to get to the desired unit (m)

• In this case, 3 to the right

G’’ M’’ k H Da base d c m

• Then move the decimal point from the original quantity the same amount

1 km = 1,000 m

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CONVERSIONS

• 387 g to kg

• 551 cm to m

• 398 ml to L

• 0.57 g to mg

• 58700 cm to km

• 0.387 kg

• 5.51 m

• 0.398 l

• 570 mg

• .587 km

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GRAPHS

• Graphing is an important procedure used by

scientists to display data collected during an

experiment.

• There are three types of graphs

• Line, Bar, Pie

• Each graph contains items that help you read

the graph and understand the data being shown

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GRAPHS • Line Graphs: Shows continuous

change, and the relationship

between two variables

• Bar Graph: Show a comparison

between similar items or events,

or representing a single value

for many items

• Pie Graph: Show the parts of a

whole, adds up to 100%

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GRAPHS

• Title: tells what the graph is

about. It should be a

concise statement placed

above the graph.

• Dependent variable: placed

on the y-axis (vertical)

• Independent variable:

placed on the x- axis

(horizontal)

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GRAPHS • Variable Scales: A scale is used so

you know where to plot the

points representing the data and

must include all the data points.

• The scales should start with 0

and increase by the same

amount, your data will

determine these values

• Legend: a key to reading the data

in your graph

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SCIENTIFIC NOTATION • Scientific notation is used to express really BIG or SMALL

numbers more easily.

• It is expressed as 2 factors:

• Factor #1: a number between 1 and 10

• Factor #2: a power of ten

6.8 x 104 = 68,000

• The exponent on 10 tells you the number of places to move to the decimal

• If the exponent is positive, you move to the right

• If it is negative, you move to the left 23

QUICK CONVERSIONS

• 6.7 X10-7

• 2.31 X105

• 5.79 X103

• 4.19 X10-5

• .0065

• 94,100,000

• .000000065

• 9,840

• .00000067

• 231000

• 5790

• .0000419

• 6.5 X10-3

• 9.41 X107

• 6.5 X10-8

• 9.84 X103

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