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Objectives Compare and contrast independent and dependent variables. Compare and contrast experimentation and investigation. Identify the differences

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ObjectivesCompare and contrast independent and dependent variables.

Compare and contrast experimentation and investigation.

Identify the differences between mass and weight.

Methods of ScientistsSection 1.2

Review Vocabulary

experiment: procedure performed in a controlled setting to test a hypothesis and collect precise data

ObjectivesExplain what scientific notation is and how it is used.

Methods of ScientistsSection 1.2

Scientists use scientific methods to structure their experiments and investigations.

New Vocabularyscientific methods

hypothesis

independent variable

dependent variable

control

Le Système International d’Unités (SI)

scientific notation

Methods of ScientistsSection 1.2

The Nature of Scientific Investigations

Scientists use similar methods to gather data and communicate information.

Scientific methods are a series of problem-solving procedures that helps scientists conduct experiments.

Methods of ScientistsSection 1.2

The Nature of Scientific Investigations

A hypothesis is a testable explanation of a situation that can be supported or disproved by careful procedures.

Methods of ScientistsSection 1.2

Visualizing Scientific Methods

Scientific methods are used by scientists to help organize and plan their experiments and investigations.

Methods of ScientistsSection 1.2

The Nature of Scientific Investigations

Experimentation

An experiment is classified as an organized procedure that involves making observations and measurements to test a hypothesis.

Methods of ScientistsSection 1.2

The independent variable in an experiment is the factor that is changed by the experimenter.

A dependent variable is a factor that is affected by changes in the independent variable.

The Nature of Scientific Investigations

Methods of ScientistsSection 1.2

The Nature of Scientific Investigations

A control is used in an experiment to show that the results of an experiment are a result of the condition being tested.

Methods of ScientistsSection 1.2

The Nature of Scientific Investigations

Investigation

An investigation involves observation and collecting data but does not include a control.

Methods of ScientistsSection 1.2

The Nature of Scientific InvestigationsAnalysis and conclusions

During a scientific experiment, all data are carefully recorded.

Once an experiment is complete, graphs, tables, and charts are commonly used to display data.

These data are then analyzed so that a conclusion can be drawn.

Methods of ScientistsSection 1.2

The Nature of Scientific Investigations

Analysis and conclusions

Many times, a conclusion does not support the original hypothesis.

In such a case, the hypothesis must be reevaluated and further research must be conducted.

Methods of ScientistsSection 1.2

Measurement

Le Système International d’Unités (SI) is a modern version of the metric system based on a decimal system.

Length

The SI unit for length is the meter (m).

Methods of ScientistsSection 1.2

Measurement

Mass

The amount of matter in an object is called mass.

The SI unit of mass is the kilogram (kg).

Methods of ScientistsSection 1.2

Measurement

Weight

Weight is a measure of the gravitational force on an object.

The SI unit for force is the newton (N).

Methods of ScientistsSection 1.2

MeasurementArea and volume

Methods of ScientistsSection 1.2

Area is the amount of surface included within a set of boundaries.

The SI unit for area is square meters (m2).

Volume is the amount of space occupied by an object.

The SI unit for volume is cubic meters (m3).

Measurement

Density

Density is the measure of the amount of matter that occupies a given space.

The SI units for density are expressed in grams per cubic centimeter (g/cm3), grams per milliliter (g/mL), and kilograms per cubic meter (kg/m3).

Methods of ScientistsSection 1.2

MeasurementTimeTime is the interval between two events.

The SI unit for time is the second (s).

Methods of ScientistsSection 1.2

Temperature is a measure of the average kinetic energy of the particles that make up a material.

The SI unit for temperature is the kelvin (K).

Absolute zero is the coldest possible temperature.

Temperature

Measurement

Temperature is a measure of the average kinetic energy of the particles that make up a material.

The SI unit for temperature is the kelvin (K).

Absolute zero is the coldest possible temperature.

Temperature

Methods of ScientistsSection 1.2

Scientific Notation

In scientific notation, a number is expressed as a value between 1 and 10 multiplied by a power of 10.

Methods of ScientistsSection 1.2

Scientific Notation

Example

The number of grains of sand on Earth is approximately 4,000,000,000,000,000,000,000 and would be written as 4 1021.

Methods of ScientistsSection 1.2

Scientific Notation

Example

The mass of Earth at 5,974,200,000,000,000,000,000,000 kg would be written as 5.9742 1024 kg.

Methods of ScientistsSection 1.2

CH Key Concepts

Section 1.1 Earth Science

Earth science encompasses five areas of study: astronomy, meteorology, geology, oceanography, and environmental science.

Earth is divided into four systems: the geosphere, hydrosphere, atmosphere, and biosphere.

Earth systems are all interdependent.

Study Guide1

CH

Identifying the interrelationships between Earth systems leads to specialties and subspecialties.

Technology is important, not only in science, but in everyday life.

Earth science has contributed to the development of many items used in everyday life.

Section 1.1 Earth Science

1 Study Guide Key Concepts

CH

Scientists use scientific methods to structure their experiments and investigations.

Scientists work in many ways to gather data.

A good scientific experiment includes an independent variable, dependent variable, and control. An investigation, however, does not include a control.

Section 1.2 Methods of Scientists

1 Study Guide Key Concepts

CH

Graphs, tables, and charts are three common ways to communicate data from an experiment.

SI, a modern version of the metric system, is a standard form of measurement that all scientists use.

To express very large or very small numbers, scientists use scientific notation.

Section 1.2 Methods of Scientists

1 Study Guide Key Concepts

CH

The number 1,280,000,000 can be written in scientific notation. Which answer choice is equal to this number?

a. 1.28 107

b. 1.28 108

c. 1.28 109

d. 1.28 1010

1.2 Section Questions

The Nature of Science1

CH

What term collectively refers to the problem-solving procedures that scientists use?

a. experiments

b. investigations

c. hypotheses

d. scientific methods

1.2 Section Questions

The Nature of Science1

CH

A rock is broken into many pieces. Which of the following measures of the rock material increased as a result?

a. mass

b. weight

c. area

d. volume

1.2 Section Questions

The Nature of Science1

CH

Which of these examples best represents a scientific model?

a. the salinity of typical ocean water

b. the size and mass of the Moon

c. a diagram of Earth’s interior

d. a picture of a volcano on Mars

Chapter Assessment Questions

The Nature of Science1

CH

The Kelvin scale is often used to measure temperature during scientific experiments. Which value is the lowest possible temperature on this scale?

a. 0

b. –100

c. –175

d. –273

Chapter Assessment Questions

The Nature of Science1

CH

Newton’s first law of motion is a scientific law. What do scientific laws provide to scientists?

a. an explanation of why things occur

b. a new idea that can be tested

c. a description of how nature behaves

d. an illustration or picture of nature

Chapter Assessment Questions

The Nature of Science1

CH

Le Système International d’Unités (SI) is the set of standard units that most scientists use for making measurements. In which unit should a person who is using the SI system express volume?

a. the square foot (ft2)

b. the square meter (m2)

c. the cubic foot (ft3)

d. the cubic meter (m3)

Chapter Assessment Questions

The Nature of Science1

CH

Why is scientific notation sometimes used when doing science?

Answer: It is sometimes necessary when doing science to use numbers that are very large or very small. These numbers can be conveniently expressed by using scientific notation.

Chapter Assessment Questions

The Nature of Science1

CH

In a scientific experiment, which factor is changed or changes to produce the observed result?

a. independent variable

b. dependent variable

c. constant

d. control

Standardized Test Practice

The Nature of Science1

CH

An object is moved from Earth to the Moon. What measure of the object changes as a result?

a. its weight

b. its mass

c. its volume

d. its density

Standardized Test Practice

The Nature of Science1

CH

What requirement must all scientific hypotheses meet?

a. They must be correct.

b. They must be simple.

c. They must be useful.

d. They must be testable.

Standardized Test Practice

The Nature of Science1

CH

a. g/cm

b. g/cm2

c. kg/m3

d. kg/m2

Which unit could be used to represent the density of an object?

Standardized Test Practice

The Nature of Science1

CH

Why are scientific research reports often put through a process of peer review before they are published?

Standardized Test Practice

The Nature of Science1

CH

Answer: The peer review process helps the publisher select reports that make the most important contributions. It also helps reduce the number of mistakes and helps to ensure that the report’s conclusions are objective and fair.

Standardized Test Practice

The Nature of Science1

CH

scientific methods

hypothesis

independent variable

dependent variable

control

Le Système International d’Unités (SI)

scientific notation

Section 1.2 Vocabulary

The Nature of Science1