Chapter 1

Science Skills

Chapter 1 Sections

• 1.1 What is Science?• 1.2 Using a Scientific Approach• 1.3 Measurement• 1.4 Presenting Scientific Data

1.1 What is ScienceKey Concepts

• How does the process of science start and end?

• What is the relationship between science and technology?

• What are the branches of natural science?

1.1 Science From Curiosity

• Science involves asking questions about nature and then finding ways to answer them.

• Curiosity is the basis of science.• Science is a system of knowledge and

the methods you use to find that knowledge.

• Science begins with curiosity and often ends with discover.

1.1 Scientific Experiments and

Answers• Scientific results are unique for

each experiment.• Observations can be qualitative or

quantitative.• Some experiments can not be

performed. Evidence must be collected to envision how an event occurs.

1.1 Science and Technology

• The goal of science is to add to the body of knowledge.

• The goal of technology is to apply that body of knowledge.

• Technology is the application of scientific knowledge to solve a practical problem, or to better people’s lives.

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

1.1 The Branches of Science

• Science is divided into the social and natural sciences.

• The natural sciences are divided into three main groups.

•Physical Science•Earth and Space Science•Life Science

1.1 The Branches of Science

1.1 Physical Science

• Physical science are the sciences that deal with the non-living things.

• The two main areas of physical science are physics and chemistry.

• Chemistry is the study of the composition and reactions of matter.

• Physics is the study of matter and energy.

1.1 Earth and Space Science

• Earth and space science are the sciences that deal with the earth and its place in the universe.

• The two main areas of the Earth sciences are geology and astronomy.

• Geology is the study of the origin , structure, and history of the earth.

• Astronomy is the study of the universe beyond earth.

1.1 Life Science

• Life science are the sciences that deal with the living organisms.

• Biology is the main science that deals with all living things.

• Biology can be further divided into zoology, botany, mycology and a myriad of other specific sciences.

1.1 Overlapping Areas of Science

• The boundary that surrounds each area of science is not always so clear.

• Biology deals with the chemistry and physics of living creatures.

• Much of geology deals with the chemistry of the rocks.

1.1 The Big Ideas of Physical Science

• The universe is 13.7 billion years old and 700 million billion billion meters in diameter.

• All matter is made of atoms and the atoms are made up of even smaller building blocks called protons, neutrons, and electrons.

1.1 The Big Ideas of Physical Science

• A push or a pull on an object is called a force. Forces cause changes in motion and can be calculated.

• Energy exists in many forms. It can change from one form to another, but it can never be destroyed. Matter can be changed to energy.

1.1 Science and Your Perspective

• Science is a process and a body of knowledge.

• Scientific facts may change in the future.

• The scientific process that discovers new facts will remain constant.

1.2 Using a Scientific Approach

Key Concepts

• What is the goal of a scientific method?

• How does a scientific law differ from a scientific theory?

• Why are scientific models useful?

1.2 Scientific Methods

• An organized plan for gathering, organizing, and communicating information is called a scientific method.

• The goal of any scientific method is to solve a problem or to better understand an observed event.

1.2 A Scientific Method

1.2 Scientific Methods

• Each step in the method involves a specific skill.

• Scientific methods can vary from case to case.

• Scientist may change the order or skip steps.

1.2 Making Observations

• Scientific investigation often begins with observation.

• An observation is information that you obtain by your senses.

• Repeatable observations are known as facts.

1.2 Forming A Hypothesis

• A hypothesis is a proposed answer to a question.

• A hypothesis can come from observation or research.

• For it to be useful, it must be testable.

1.2 Testing A Hypothesis

• Scientist test their hypothesis by doing an experiment.

• Any factor that can change is called a variable.

• Any factor that does not change is called a constant.

1.2 Testing A Hypothesis

• The manipulated variable is the variable that causes a change in another. (Independent Variable)

• The responding variable is the variable that changes in response to the manipulated variable. (Dependent Variable)

• A controlled experiment is an experiment in which only one variable is changed at a time.

1.2 Drawing A Conclusion

• Based on the analysis of your data, you decide whether or not your hypothesis is supported.

• For the hypothesis to be considered valid and widely accepted, the experiment must result in the exact same data every time it is repeated.

1.2 Developing A Theory

• A scientific theory is a well tested explanation for a set of observations or experimental results.

• Theories are never proven to be true, the facts only continue to support them.

• If they fail to explain new facts or discoveries, then they can be revised or replace by a new theory.

1.2 Scientific Laws

• A scientific law is a statement that summarizes a pattern found in nature.

• A scientific law describes an observed pattern in nature without attempting to explain it. The explanation of such a pattern is provided by a scientific theory.

1.2 Scientific Models

• A model is a representation of an object or an event.

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

1.2 Scientific Models

• A model can be a physical structure or a mental concept.

• As long as the model lets you mentally picture the concept it is to represent, then the model is doing its job.

• Models change as our knowledge of how things work.

1.2 Working Safely in Science

• Scientist working in labs often work with dangerous materials.

• It is important to follow safety precautions at all times.

• Study the rules in the Science Safety section of the Skills Handbook.

• Always follow the teacher’s instructions and the textbook directions exactly.

1.3 MeasurementsKey Concepts

• Why is scientific notation useful?• What units do scientist use for

their measurements?• How does the precision of

measurements affect the precision of scientific calculations?

1.3 Scientific Notation

• Scientist work with very big and very small numbers. They have developed a shortcut for these numbers.

• Scientific notation is a way of expressing a value as the product of a number between 1 and 10 and a power of 10.

1.3 Scientific Notation

• 75,000,000 is written as….• 7.5 X 107

• 1 7.5 10• 0.0079 is written as….• 7.9 X 10-3

• 1 7.9 10• Scientific notation makes very large

or very small numbers easier to work with.

1.3 Scientific Notation

• When multiplying scientific notation, you multiply the base numbers and add the exponents.• (7.0 X 105 m/s) X (2.0 X 104 s) =

• 1.4 X 1021 m• When dividing scientific notation, you

divide the base numbers and subtract the exponents.• (2.2 X 1011 m) / (2.0 X 108 m/s) =

• 1.1 X 103 s

1.3 SI Units of Measurement

• When expressing measurements, you should always include a unit.

• Many of the units you are familiar with are not units used in science.

• Scientist use a set of measuring units called SI, or International System of Units.

• These are a revision of the metric system.

1.3 Base Units

• SI is built upon seven metric units, known as base units.

• Length is the straight line distance between two points. Its base unit is the meter (m)

• Mass is the quantity of matter in an object. Its base unit is the kilogram (kg)

1.3 Base Units

1.3 Derived Units

• Additional SI units can be found by combining the base units. These are called derived units.

• Volume is the amount of space an object takes up.

• L X W X H• (m) X (m) X (m) =• m3

1.3 Derived Units

• Density is the ratio of an objects mass to its volume. It requires a derived unit.• Density = [Mass] / [Volume]• Units of Density = [kg] / [m3]

1.3 Metric Prefixes

• The base unit is not always the right unit to use. It could be too big or too small.

• A metric prefix indicates how many times a unit should be multiplied or divided by 10.

1.3 SI Prefixes

1.3 Conversion

• To convert from one metric unit to another metric unit use a conversion factor.

• A conversion factor is a ratio of equivalent measurements.

• (1 m) / (1000 mm) • or

• (1000 mm) / (1 m)

1.3 Example

• Suppose you had 1.675 grams but you need to know the mass in milligrams.• 1.675 g X (1000 mg) / (1g) =

• 1,675 mg

1.3 Limits of Measurement

• The exactness of a measurement is referred to as precision.

• Significant figures are all the digits that are known in a measurement plus the last digit that is estimated.

• The precision of a calculated answer is limited by the least precise measurement used in the calculation.• Density = (45.97 g) / (3.9 mL) = ?

• 11.78717949 g/mL• 12 g/mL

1.3 Limits of Measurement

• Accuracy is the closeness of a measurement to the actual value of what is being measured.

1.3 Measuring Temperature

• A thermometer is an instrument that measures the temperature of an object.

• You are familiar with two temperature scales (Celsius, Fahrenheit)

1.3 Measuring Temperature

• On the Fahrenheit scale water freezes at 32OF and boils at 212OF.

• On the Celsius scale water freezes at 0OC and boils at 100OC.

• OC = (5/9)(OF – 32)• OF = ((9/5)OF) + 32

1.3 Measuring Temperature

• The SI unit of temperature is the kelvin (K).

• The lowest temperature possible is 0 K. This is called absolute zero and it is –273.15OC.

• K = OC + 273

1.4 Presenting Scientific Data

Key Concepts• How do scientist organize data?• How can scientists communicate

experimental data?

1.4 Organizing Data

• Scientist can organize their data by using tables and graphs.

• The simplest way to present data is in a table.

1.4 Line Graphs

• A line graph is useful for showing trends in data.

• In a line graph, the independent variable is found on the x-axis.

• The dependent variable is located on the y-axis.

• The slope of the line is the ratio of a vertical change to the horizontal change. Slope =

Rise

Run

1.4 Line Graphs

• A line graph can show many different relationships.

• A direct proportion is a relationship in which the ratio of the two variables is constant.

Direct Proportion

0

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Time (s)D

ista

nce

(m)

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y = mx + b

1.4 Line Graphs

• An inverse proportion is a relationship in which the product of the two variables is constant.

Inverse Proportion

0

0.2

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Time (s)D

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y =1

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1.4 Bar Graphs

• A bar graph is used to show comparisons between data sets.

Bar Graph

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1 2 3 4 5 6 7 8 9 10

Time (s)Sp

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CarVanTruck

1.4 Circle Graphs

• A circle graph is used to parts of a whole.

Composition of Earth's Crust

46%

27%

8%

5%

4%3%3%2%2%

Oxygen

Silicon

Aluminum

Iron

Calcium

Sodium

Potassium

Magnesium

Other

1.4 Communicating Data

• Scientist can communicate results by writing in scientific journals or speaking at conferences.

• Different scientist may interpret the data in the same or in a different way.

• Peer review encourages comments, suggestions, questions, and criticism from other scientist.

• This allows for verification of results and general acceptance of theories.