Introduction to Science

Introduction to Science Physical Science Chapter 1 Physical Science Chapter 1

Chapter Outline • The Nature of Science • How science takes place • The branches of science • Scientific laws and theories • The Way Science Works • Science skills and scientific method • Units of measurement and unit conversions • Organizing Data • Presenting scientific data using graphs and tables • Writing numbers in scientific notation • Using significant figures Physical Science Chapter 1

Why it matters • The knowledge and skills gained in unit will serve as a foundation for the study of science. Physical Science Chapter 1

Myths vs. Facts • Myth: learning is the passive transfer of knowledge • Fact: learning is dynamic and involves continuously questioning information • Myth: science is a static, faithful copy of the world • Fact: science is a human construction based on the most logical interpretation of experiment and theory Physical Science Chapter 1

Discuss • Do you understand each of the graphic organizers on page 4? • Which type do you like best? Physical Science Chapter 1

How Science Takes Place • How do scientists explore the world? • A scientist may perform experiments to find a new aspect of the natural world, to explain a known phenomenon, to check the results of other experiments, or to test the predictions of current theories. Physical Science Chapter 1

How Science Take Place, continued • Scientists investigate. • Scientists plan experiments. • Scientists observe. • Scientists always test the results. Physical Science Chapter 1

The Branches of Science • How are the many types of science organized? • Most of the time, natural science is divided into biological science, physical science and Earth science. • science: 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 Physical Science Chapter 1

The Branches of Science, continued • The branches of science work together. • biological science: the science of living things • botany, ecology • physical science: the science of matter and energy • chemistry: the science of matter and its changes • physics: the science of forces and energy • earth science: the science of the Earth, the atmosphere, and weather • geology, meteorology Physical Science Chapter 1

Visual Concept: Natural Science Physical Science Chapter 1

The Branches of Science,continued • Science and technology work together. • pure science: the continuing search for scientific knowledge • Advances in science and technology depend on each other. • technology: the application of science for practical purposes Physical Science Chapter 1

Scientific Laws and Theories • What are scientific theories, and how are they different from scientific laws? • Theories explain why something happens, laws explain how something works. • law: a descriptive statement or equation that reliably predicts events under certain conditions • theory: a system of ideas that explains many related observations and is supported by a large body of evidence acquired through scientific investigation Physical Science Chapter 1

Scientific Laws and Theories, continued • Experimental results support laws and theories. • Scientific theories are always being questioned and examined. To be valid, a theory must: • explain observations • be repeatable • be predictable Physical Science Chapter 1

Scientific Laws and Theories, continued • Mathematics can describe physical events. • qualitative statement: describes something with words • quantitative statement: describes something with mathematical equations Physical Science Chapter 1

Scientific Laws and Theories, continued • Theories and laws are always being tested. • Models can represent physical events. • model: a representation of an object or event that can be studied to understand the real object or event • Scientists use conceptual, physical, and computer models to study objects and events. • We use models in our everyday lives. Physical Science Chapter 1

Discuss • What are the two branches of physical science? • What are three types of models used by scientists? • Compare and contrast a scientific law and a scientific theory. Physical Science Chapter 1

Science Skills • How can I think and act like scientist? • Identifying problems, planning experiments, recording observations, and correctly reporting data are some of the most important science skills. • Scientists approach a problem by thinking logically. Physical Science Chapter 1

Science Skills, continued • Critical thinking helps solve problems logically. • critical thinking: the ability and willingness to assess claims critically and to make judgments on the basis of objective and supported reasons • Scientists use scientific methods to solve problems. • scientific method: a series of steps followed to solve problems including collecting data, formulating a hypothesis, testing the hypothesis, and stating conclusions • The scientific methods are general description of scientific thinking rather than an exact path for scientists to follow. Physical Science Chapter 1

Science Skills, continued • Scientists test hypotheses. • hypothesis:a possible explanation or answer that can be tested • Scientists test a hypothesis by doing a controlled experiment. • controlled experiment: an experiment in which the variables that could affect the experiment are kept constant (controlled) except for the one that you want to measure • variable:a factor that changes in an experiment in order to test a hypothesis Physical Science Chapter 1

Science Skills, continued • Experiments test ideas. • No experiment is a failure. • The results of every experiment can be used to revise the hypothesis or plan tests of a different variable. • Peer-reviewed research: research thathas been reviewed by other scientists Physical Science Chapter 1

Science Skills, continued • Scientists use special tools. • There are many tools used by scientists for making observations, including • telescopes • spectroscopes • particle accelerators Physical Science Chapter 1

Units of Measurement • How do scientists measure things? • Scientists use standard units of measure that together form the International System of Units, or SI. Physical Science Chapter 1

Units of Measurement, continued • SI units are used for consistency. • SI has seven base units. • derived units: combinations of the base units Physical Science Chapter 1

SI (Le Système Internationale d’Unités) Physical Science Chapter 1

Units of Measurement, continued • SI prefixes are for very large and very small measurements. • The prefixes are multiples of ten. • SI prefixes for large measurements Physical Science Chapter 1

Units of Measurement, continued • SI prefixes for small measurements Physical Science Chapter 1

Units of Measurement, continued • Measurements quantify your observations. • 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 Physical Science Chapter 1

Discuss • When might a scientist change a hypothesis? • A student needs to measure the volume of a liquid. What tool could the student use? • Look at Figure 1 on page 14. Answer the question in the caption. Physical Science Chapter 1

Conversions • Method that always works: • Write conversion factors as fractions that equal 1 • Multiply by fractions created • Repeat until you get the units you want Physical Science chapter 2

Example • Using the conversion factor 1 inch = 2.54 cm, convert 8.5 inches to cm. • Write conversion factor as fractions Physical Science chapter 2

Conversion factor fractions both equal 1 • We can multiply by them without changing the value • To decide which fraction to use, look at units of what is being converted Physical Science chapter 2

Given: 8.5 inches • We want inches to cancel out, so it needs to be in the denominator Physical Science chapter 2

Example • Using the conversion factor 1 m = 100 cm, convert 3.2 m to cm. • Write conversion factor as fractions Physical Science chapter 2

Given: 3.2 m • We want m to cancel out, so it needs to be in the denominator Physical Science chapter 2

SI shortcut • Measurement in SI is based on multiples of 10. • To multiply or divide by multiples of 10, you just move the decimal point. Physical Science chapter 2

Using the prefix table • Count the number of columns you move in the table. • Move the decimal point the same number of places and in the same direction • If converting from a smaller unit to a larger one (like cm to km), move the decimal to the left. (remember “ to Larger; to Left) • If converting from a larger unit to a smaller one (like kg to mg), move the decimal to the right. Physical Science chapter 2

Example • Convert 3.2 m to cm • Move two columns to the right. • Move decimal point two places to the right. • 320 cm • How to show your work: Physical Science chapter 2

Example • Convert 500 mg to kg • Move six columns to the left. • Move decimal point six places to the left. • 0.0005 kg Physical Science chapter 2

You Try • Convert 5 dm to m • Move one column to the left. • Move decimal point one place to the left. • 0.5 m Physical Science chapter 2

You Try • Convert 567 cm to mm • Move one column to the right. • Move decimal point one place to the right. • 5670 mm Physical Science chapter 2

Introduction to Science