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Section 1 The Nature of Science

Objectives

• Describe the main branches of natural science and relate them to each other.

• Describe the relationship between science and technology.

• Distinguish between scientific laws and scientific theories.

• Explain the roles of models and mathematics in scientific theories and laws.

Chapter 1



How Does Science Take Place?

• Scientists investigate.

• Scientists plan experiments.

• Scientists observe.

• Scientists always test the results.

Section 1 The Nature of ScienceChapter 1



How Does Science Take Place? continued

• Science has many branches.

• Biological science is the science of living things.

• Physical science is the science of matter and energy.

• Earth science is the science of the Earth, the atmosphere, and weather.

• Science is the knowledge obtained by observing natural events and conditions in order to discover facts and formulate laws or principles that can be verified or tested.




Natural Science




Biology




Physics




Earth Sciences




How Does Science Take Place? continued

• Science and technology work together.

• Some scientists practice pure science defined as

the continuing search for scientific knowledge.

• Some scientists and engineers practice applied

science defined as the search for ways to use

scientific knowledge for practical applications.

• Technology is the application of science for practical

purposes.




Scientific Laws and Theories

• Laws and theories are supported by experimental

results.

• Scientific theories are always being questioned and

examined. To be valid, a theory must:

• explain observations

• be repeatable

• be predictable




Scientific Laws and Theories, continued

• Scientific law a summary of many experimental

results and observations; a law tells how things work

• Scientific theory an explanation for some

phenomenon that is based on observation,

experimentation, and reasoning




Comparing Theories and Laws





• Mathematics can describe physical events.

• A qualitative statement describes something with

words.

• A quantitative statement describes something with

mathematical equations.





• Theories and laws are always being tested.

• Models can represent physical events.

• A model is a representation of an object or event

that can be studied to understand the real object

or event.

• Scientists use physical and computer models to

study objects and events.




Wanted Elements ProjectPhysical Science Project

“Wanted” Elements

Name: _____________________________

Date: ______________________________

Period: _____________________________

Your assigned Element: ___________________

DUE DATE:

__________________

DIRECTIONS: Create a “wanted poster” for your assigned element.

INCLUDE:

½ poster board in size

MUGSHOT: picture of your element

FINGERPRINT: chemical structure of your element (Bohr model)

NAME: name of element plus include any known aliases (Latin, Greek, Russian, etc…)

HEIGHT: atomic radius

WEIGHT: atomic mass

DISTINGUISHING CHARACTERISTICS: „characteristics‟ of your element (minimum of 5)

DANGERS: why is it “wanted” (why is it dangerous)

AMOUNT OF REWARD: cost of element ($$$)

OTHER: any other information that you think might be important for the “capture” of your element

PRISONER NUMBER: atomic number

CAPTURED BY: who gets credit for the discovery of the element and what date it was discovered on.

REFERENCES:

Cite your references on the back of your poster.

If you use a website(s), cite the actual site you use to obtain the information, not simply www.google.com.

http://www.google.com/



Atomic Model for Helium



Models




Physical, Mathematical, and Conceptual

Models




Section 2 The Way Science Works

Objectives

• Understand how to use critical thinking skills to solve

problems.

• Describe the steps of the scientific method.

• Know some of the tools scientists use to investigate

nature.

• 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, and

convert measurements.

Chapter 1



Bellringer

Your teacher has given you the following assignment:

Investigate the impact on plant growth of adding various

amounts of fertilizer to potted plants. Think about what

you would need to do to be certain that the fertilizer was

having the impact on the plant growth. Then answer the

items below.

Section 2 The Way Science WorksChapter 1



Bellringer

Place a Y besides items that would be part of your plan to investigate plant height and fertilizer. Place a N besides items that will not help you investigate this particular connection.

a. _______ Put one plant in a sunny windowsill and one in a dark corner.

b. _______ Give plants the same amounts of water.

c. _______ Give different plants different amounts of fertilizer without keeping track of which plant got extra fertilizer.

d. _______ Use some new plants from seeds and some old plants that have been growing for months.

e. _______ Start with plants that are the same size.

f. _______ Keep all plants in a similar location.

g. _______ Carefully note amounts of fertilizer each plant is given.

h. _______ Keep one plant fertilized but with no water.




Bellringer

2. Name at least five tools or supplies will you need to

perform this experiment.

3. What quantities will be measured, and what units will

you use to record these measurements?




Science Skills

• Critical Thinking

• Scientists approach a problem by thinking

logically.

• Critical thinking is the ability and willingness to

assess claims critically and to make judgments on

the basis of objective and supported reasons.




Science Skills, continued

• Using the scientific method

• The scientific method is a general description of

scientific thinking rather than an exact path for

scientists to follow.

• Scientific method a series of steps followed to solve

problems including collecting data, formulating a

hypothesis, testing the hypothesis, and stating

conclusions




Scientific Method





• Testing hypotheses

• Scientists test a hypothesis by doing a controlled experiment.

• In a controlled experiment, all the factors that could affect the experiment are kept constantexcept for one change.

• Hypothesis a possible explanation or answer that can be tested

• Variable a factor that changes in an experiment in order to test a hypothesis




Hypothesis




Controlled Experiment and Variable





• Conducting experiments

• No experiment is a failure

• The results of every experiment can be used to

revise the hypothesis or plan tests of a different

variable.





• Using scientific tools

• There are many tools used by scientists for

making observations, including

• microscopes

• telescopes

• spectroscopes

• particle accelerators

• computers




Units of Measurement

• SI units are used for consistency.• Scientists use the International System of Units (SI) to make

sharing data and results easier.




SI (Le Système Internationale d’Unités)




Units of Measurement, continued

SI prefixes are for very large and very small

measurements.

• The table below shows SI prefixes for large

measurements.





• The table below shows SI prefixes for small

measurements.




Math Skills

Conversions A roll of copper wire contains 15 m of

wire. What is the length of the wire in centimeters?

1. List the given and unknown values.

Given: length in meters, l = 15 m

Unknown: length in centimeters = ? cm




Math Skills

2. Determine the relationship between units.

Looking at the table of prefixes used for small

measurements, you can find that 1 cm = 0.01 m.

This also means that 1 m = 100 cm.

You will multiply because you are converting from a

larger unit (meters) to a smaller unit (centimeters)

3. Write the equation for the conversion.

length in cm = m

100 cm

1 m




Math Skills

length in cm = 1500 cm

4. Insert the known values into the equation, and solve.

length in cm = 15 m

100 cm

1 m





• Making measurements

• Many observations rely on quantitative

measurements.

• Length a measure of the straight-line distance

between two points

• Mass a measure of the amount of matter in an object

• Volume a measure of the size of a body or region in

three-dimensional space

• Weight a measure of the gravitational force exerted

on an object




Volume




Section 3 Organizing Data

Objectives

• Interpret line graphs, bar graphs, and pie charts.

• Use scientific notation and significant figures in

problem solving.

• Identify the significant figures in calculations.

• Understand the difference between precision and

accuracy.

Chapter 1



Bellringer

Imagine your teacher asked you to study how providing

different amounts of fertilizer affected the heights of

plants. You perform a study and collect the data shown

in the table below. Use this data to answer the items

that follow.

Section 3 Organizing DataChapter 1



Bellringer, continued

1. Which amount of fertilizer produced the tallest plants?

2. Which amount of fertilizer produced the smallest plants?

3. Plot the data on a grid like the one below.

4. Describe the overall trend as more fertilizer is added to the plants.




Presenting Scientific Data

• Line graphs are best for continuous change.

• Line graphs are usually made with the x-axis

showing the independent variable and the y-axis

showing the dependent variable.

• The values of the dependent variable depend on

what happens in the experiment.

• The values of the independent variable are set

before the experiment takes place.




Line Graph




Presenting Scientific Data, continued

• Bar graphs compare items.

• A bar graph is useful for comparing similar data for

several individual items or events.

• A bar graph can make clearer how large or small

the differences in individual values are.




Bar Graph




Presenting Scientific Data, continued

• Pie charts show parts of a

whole.

• A pie chart is ideal for

displaying data that are

parts of a whole.

• Data in a pie chart is

presented as a

percent.




Writing Numbers in Scientific Notation

• Scientific notation is a method of expressing a

quantity as a number multiplied by 10 to the

appropriate power.

• Some powers of 10 and their decimal equivalents are

shown below.

• 103 = 1000

• 102 = 100

• 101 = 10

• 100 = 1

• 10-1 = 0.1

• 10-2 = 0.01

• 10-3 = 0.001




Writing Numbers in Scientific Notation,

continued

• Using scientific notation

• When you use scientific notation in calculations,

you follow the math rules for powers of 10.

• When you multiply two values in scientific

notation, you add the powers of 10. When you

divide, you subtract the powers of 10.




Math Skills

Writing Scientific Notation The adult human heart

pumps about 18 000 L of blood each day. Write this

value in scientific notation.


Given: volume, V = 18 000 L

Unknown: volume, V = ? x 10? L




Math Skills, continued

2. Write the form for scientific notation.

V = ? x 10? L

3. Insert the known values into the form, and solve.

First find the largest power of 10 that will divide into

the known value and leave one digit before the

decimal point. You get 1.8 if you divide 10 000

into 18 000 L.

So, 18 000 L can be written as (1.8 x 10 000) L





Then write 10 000 as a power of 10.

Because 10 000 = 104, you can write 18 000 L as

1.8 x 104 L.


V = 1.8 x 104 L



Scientific Notation




Math Skills

Using Scientific Notation Your state plans to buy a

rectangular tract of land measuring 5.36 x 103 m by

1.38 x 104 m to establish a nature preserve. What is

the area of this tract in square meters?


Given: length, l = 1.38 x 104 m

width, w = 5.36 x 103 m

Unknown: area, A = ? m2





2. Write the equation for area.A = l w

3. Insert the known values into the equation, and

solve.

A = (1.38 104 m) (5.36 103 m)

Regroup the values and units as follows.

A = (1.38 5.36) (104 103) (m m)

When multiplying, add the powers of 10.

A = (1.38 5.35) (104+3) (m m)

A = 7.3968 107 m2

A = 7.40 107 m2




Using Significant Figures

Precision and accuracy

• Precision the exactness of a measurement

• Accuracy a description of how close a measurement

is to the true value of the quantity measured

• Significant figure a prescribed decimal place that

determines the amount of rounding off to be done

based on the precision of the measurement




Accuracy and Precision, part 1




Accuracy and Precision, part 2




Accuracy and Precision




Using Significant Figures, continued

• When you use measurements in calculations, the

answer is only as precise as the least precise

measurement used in the calculation.

• The measurement with the fewest significant figures

determines the number of significant figures that can

be used in the answer.




Math Skills

Significant Figures Calculate the volume of a room

that is 3.125 m high, 4.25 m wide, and 5.75 m long.

Write the answer with the correct number of

significant figures.


Given: length, l = 5.75 m

width, w = 4.25 m

height, h = 3.125 m

Unknown: Volume, V = ? m3





2. Write the equation for volume.V = l w h

3. Insert the known values into the equation, and solve.V = 5.75 m 4.25 m 3.125 mV = 76.367 1875 m3

The answer should have three significant figures, because the value with the smallest number of significant figures has three significant figures.


V = 76.4 m3



Significant Figures




Concept Mapping




Understanding Concepts

1. During a storm, rainwater depth is measured every

15 minutes. Which of these terms describes the

depth of the water?

A. controlled variable

B. dependent variable

C. independent variable

D. significant variable

Standardized Test PrepChapter 1



Understanding Concepts, continued

1. During a storm, rainwater depth is measured every

15 minutes. Which of these terms describes the

depth of the water?

A. controlled variable

B. dependent variable

C. independent variable

D. significant variable





2. Why were scientists unable to form a theory that diseases

are caused by bacteria before the late fifteenth century?

F. No on tried to understand the cause of disease until

then.

G. Earlier scientists were not intelligent enough to

understand the existence of bacteria.

H. The existence of microbes could not be discovered

until the technology to make high-quality lenses had

been developed.

I. Doctors believed they understood the disease

process, so they would not accept new ideas about

the causes.





3. What is a scientific theory?

A. A theory is a guess as to what will happen.

B. A theory is a summary of a scientific fact based

on observations.

C. A theory is an explanation of how a process

works based on observations.

D. A theory describes a process in nature that can

be repeated by testing.





4. When designing a new airplane, experienced pilots use computer simulations to determine how changes from previous designs affect the plane‟s handling in flight. What is the advantage of computer simulation over actually building the plane and having pilots test it in actual flight situations?





4. When designing a new airplane, experienced pilots use computer simulations to determine how changes from previous designs affect the plane‟s handling in flight. What is the advantage of computer simulation over actually building the plane and having pilots test it in actual flight situations?

Answer: The computer simulation provides a model of the new plane so that potential design problems can be corrected without risk to the pilots and without the expense of building an airplane that does not function well.




Reading Skills

Two thousand years ago Earth was believed to be unmoving and at the center of the universe. Tthe moon, sun, each of the known planets, and all of the stars were believed to be located on the surfaces of rotating crystal spheres. Motion of the celestial objects could be predicted based on the complex movement of the spheres that had been determined using observations recorded over many years.

5. Demonstrate why this description of the universe was a useful model to ancient astronomers but not to present-day astronomers.




Reading Skills, continued

5. [See previous slide for question.]

Answer: It was useful because it could predict motions of objects in the sky.




Interpreting Graphics

6. What is the volume of

the gas 40 seconds

into the experiment?

F. 15 mL

G. 24 mL

H. 27 mL

I. 50 mL




Interpreting Graphics, continued

6. What is the volume of

the gas 40 seconds

into the experiment?

F. 15 mL

G. 24 mL

H. 27 mL

I. 50 mL


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