Safety In the Science Lab

 

Safety In the Science Lab 

Watch this video about Experimenting with Safety

NTSA Safety in the Science Classroom

 

National Science Teacher's Association

 Standards of Student Conduct in the Laboratory and in the Field

1. Conduct yourself in a responsible manner at all times in the laboratory. Frivolous activities, 

    mischievous behavior, throwing items, and conducting pranks are prohibited.

2. Lab and safety information and procedures must be read ahead of time. All verbal and written
    instructions shall be followed in carrying out the activity or investigation.

3. Eating, drinking, gum chewing, applying cosmetics, manipulating contact lenses, and other unsafe
    activities are not permitted in the laboratory.

4. Working in the laboratory without the instructor present is prohibited.

5. Unauthorized activities or investigations are prohibited. Unsupervised work is not permitted.

6. Entering preparation or chemical storage areas is prohibited at all times.

7. Removing chemicals or equipment from the laboratory is prohibited unless authorized by the
    instructor.

Personal Safety

8. ANSI Z87.1 approved chemical splash goggles or safety glasses, as appropriate or directed by your
    instructor, shall be worn at all times in the laboratory or field, including pre-laboratory work and
    clean-up, unless the instructor specifically states that the activity does not require the use of
    chemical splash goggles or safety glasses.

9. When an activity requires the use of laboratory aprons, the apron shall be appropriate to the size of
    the student and the hazard associated with the activity or investigation. The apron shall remain tied
    throughout the activity or investigation.

10. All accidents, chemical spills, and injuries must be reported immediately to the instructor, no
     matter how trivial they may seem at the time. Follow your instructor’s directions for immediate

     treatment.

11. Dress appropriately for laboratory work by protecting your body with clothing and shoes. This
      means that you should use hair ties to tie back long hair and tuck into the collar. Do not wear
      loose or baggy clothing or dangling jewelry on laboratory days. Acrylic nails are also a safety
      hazard near heat sources and should not be used. Sandals or open-toed shoes are not to be worn
      during any lab activities. Refer to prelab instructions. If in doubt, ask!

12. Know the location of all safety equipment in the room. This includes eye wash stations, the
      deluge shower, fire extinguishers, the fume hood, and the safety blanket. Know the location of
      emergency master electric and gas shut offs and exits.

13. Certain classrooms may have living organisms including plants in aquaria or other containers.
      Students must not handle organisms without specific instructor authorization. Wash your hands
      with soap and water after handling organisms and plants.

14. When an activity or investigation requires the use of laboratory gloves for hand protection, the
      gloves shall be appropriate for the hazard and worn throughout the activity.

Specific Safety Precautions Involving Chemicals and Lab Equipment

15. Avoid inhaling in fumes that may be generated during an activity or investigation.

16. Never fill pipettes by mouth suction. Always use the suction bulbs or pumps.

17. Do not force glass tubing into rubber stoppers. Use glycerin as a lubricant and hold the tubing
      with a towel as you ease the glass into the stopper.
18. Proper procedures shall be followed when using any heating or flame producing device especially
      gas burners. Never leave a flame unattended.

19. Remember that hot glass looks the same as cold glass. After heating, glass remains hot for a very
      long time. Determine if an object is hot by placing your hand close to the object but do not touch
      it.

20. Should a fire drill or other evacuation emergency occur during an investigation or activity, make
      sure you turn off all gas burners and electrical equipment and exit the room as directed.

21. Always read the reagent bottle labels twice before you use the reagent. Be certain the chemical
     you use is the correct one.

22. Replace the top on any reagent bottle as soon as you have finished using it and return the reagent
      to the designated location.

23. Do not return unused chemicals to the reagent container. Follow the instructor’s directions for the
      storage or disposal of these materials.

Standards For Maintaining a Safer Laboratory Environment

24. Backpacks and books are to remain in an area designated by the instructor and shall not be
      brought into the laboratory area.

25. Never sit on laboratory tables.

26. Work areas should be kept clean and neat at all times. Work surfaces are to be cleaned at the end
      of each laboratory or activity.

27. Solid chemicals, metals, matches, filter papers, broken glass, and other materials designated by
      the instructor are to be deposited in the proper waste containers, not in the sink. Follow your
      instructor’s directions for disposal of waste.

28. Sinks are to be used for the disposal of water and those solutions designated by the instructor.
      Other solutions must be placed in the designated waste disposal containers.

29. Glassware is to be washed with hot, soapy water and scrubbed with the appropriate type and sized
      brush, rinsed, dried, and returned to its original location.

30. Goggles are to be worn during the activity or investigation, clean up, and through hand washing.
 

Eyewash Sign	Safety Shower Sign	First Aid Sign	Defibrillator Sign
Fire Blanket Safety Sign	R Radiation Symbol	Biohazard	Radioactive Symbol

Ionizing Radiation Symbol

Recycling Symbol

Skull and Crossbones

Toxic

PreviousNext

Harmful or Irritant	Flammable	Explosives	Oxidizing
Corrosive	Environmental Hazard	Respiratory Protection Sign	Gloves Required Symbol
Eye or Face Protection Symbol	Protective Clothing Sign	Protective Footwear Sign	Eye Protection Required Sign

Chemical Weapon Symbol	Biological Weapon Symbol	Nuclear Weapon Symbol

 

Welcome to T.C. Marsh Middle School 7th Grade Science

Welcome to T.C. Marsh Middle School 7th Grade Science!

 

Everything you wanted to know!

Textbook: Glencoe 7th Grade Science

Course Description:  Science is the systematic knowledge derived through experimentation, observation and study. In addition, the methodology used to acquire this knowledge. Most importantly, science is about thinking and asking questions, creating hypotheses and experimenting.

 

What will we study this year?
Life! 

specifically...we will study... 

Structure of Organisms- Plants/Animals 

Genetics & Adaptations
Body Systems 
Elements & Compounds

Matter & Energy
Organisms & Environments

Earth & Space

 

Science Journal: As part of our curriculum, we are going to create Interactive Science Journals. It will be key to success in science class this year, as well as 8^th grade test preparation materials. It will contain notes, handouts and valuable information concerning class material. It will also contain students’ thoughts, creativity and personality.  
 

The Science Journal must come to class everyday! This is essential!

What supplies will you need for class?

            1. 5 Subject notebook
            2. #2 pencils
            3. Stick Glue
            4. Colored pencils
            5. 1 Paper towels or Kleenex
            6. 1 Ream of print paper
            7. Construction paper
            7. Highlighters

Grading Procedures:
A = 90 and above              B = 80 – 89                        C = 70-79                  F = 69 and below

Grading Weight: 

Grades will be weighted as follows:  45%     Classwork/Homework
20%     Tests
20%      Projects/Products (ex: composition, research paper, presentation, report)
15%      Six-week test grade

Classroom Norms

Classroom Rules:
Stay focused on learning
Make no excuses
Be respectful
Be prepared

Privileges:
Academic success
Praise and recognition
Positive parent contact
Classroom/school rewards
Self-gratification for a job well done

Consequences:
Warning or withdrawal of privileges
Student-teacher conference
Parent contact
Detention
Teacher/parent conference Assistant principal

1st week of school classroom information
Science Safety Power Point

Science Tools

What is science?

The last time that you watched squirrels play in a park or in your yard, did you realize that you were practicing science? Every time you observe the natural world, you are practicing science. Science is the investigation and exploration of natural events and of the new information that results from those investigations.

When you observe the natural world, you might form questions about what you see. While you are exploring those questions, you probably use reasoning, creativity, and skepticism to help you find answers to your questions. People use these behaviors in their daily lives to solve problems, such as how to keep a squirrel from eating bird seed, as shown in Figure 1.

 

Similarly, scientists use these behaviors in their work. Scientists use a reliable set of skills and methods in different ways to find answers to questions. After reading this lesson, you will have a better understanding of how science works, the limitations of science, and scientific ways of thinking. In addition, you will recognize that when you practice science at home or in the classroom, you use scientific methods to answer questions just as scientists do.

(l) Kelly Jett/Alamy, (r) Natural Visions/Alamy

Figure 1 Someone used reasoning and creativity to design each of these squirrel-proof bird feeders. However, some solutions don’t work. Scientists use similar methods to try to solve problems.

 

5 NOTES

Branches of Science

Life Science

Earth Science

Physical Science

Teacher Demo

Branches of Science

There are three main fields of science: life science, Earth science, and physical science.

Life Science

Life science is the study of all living things. Use the questions below to see what students already know about this field.

Guiding Questions

What is another name for life science?

It is also called biology.

What kind of interactions might this forest ecologist be studying?

Students should conclude that the scientist is studying the interactions of the lichens with the Douglas fir trees.

What are examples of living things?

Students should understand that animals, plants, and microscopic organisms all are living things.

Earth Science

Earth scientists study our planet’s landforms, rocks, soils, and interior. Astronomy is also part of Earth science.

Guiding Questions

What natural Earth science topic might these scientists be studying?

They might be studying soil content.

What other parts of Earth can you think of that would logically be part of Earth science?

The oceans and atmosphere are parts of Earth, so they are also part of Earth science.

Physical Science

The two main fields of physical science are physics and chemistry.

Guiding Questions

In general terms, what do physicists and chemists study?

They study the interactions of matter and energy.

The chemist in the photo is preparing antibiotic solutions. How do chemistry and other sciences work together in the development of antibiotics?

Biology, the study of life, is key to understanding how antibiotics are processed by the body. Biochemists work with biology and chemistry.

Teacher Demo

Which Branch of Science? Display a seed, a rock, a melting ice cube, an insect (or a photo of one), a flashlight, a photo of a cloud, and a plant.

Ask: Which of these objects would be studied by a biologist? Why?

A biologist would study the seed, insect, and plant. They are all living things.

Ask: Which of these objects would be studied by a physicist? Why?

A physicist would study the melting ice cube and flashlight. The objects show the interaction of matter and energy.

Ask: Which of these objects would be studied by an Earth scientist? Why?

An Earth scientist would study the rock and cloud. They are both parts of Earth.

Branches of Science

No one person can study all the natural world. Therefore, people tend to focus their efforts on one of the three fields or branches of science—life science, Earth science, or physical science, as described below. Then people or scientists can seek answers to specific problems within one field of science.

MARK MOFFETT/MINDEN PICTURES/National Geographic Stock

Life Science
Biology, or life science, is the study of all living things. This forest ecologist, a life scientist who studies interactions in forest ecosystems, is studying lichens growing on Douglas firs. Biologists ask questions such as
• How do plants produce their own food?
• Why do some animals give birth to live young and others lay eggs?
• How are reptiles and birds related?

Frans Lanting/CORBIS

Earth Science
The study of Earth, including its landforms, rocks, soil, and forces that shape Earth’s surface, is Earth science. These Earth scientists are collecting soil samples in Africa. Earth scientists ask questions such as
• How do rocks form?
• What causes earthquakes?
• What substances are in soil?

Ryan McVay/Getty Images

Physical Science
The study of chemistry and physics is physical science. Physical scientists study the interactions of matter and energy. This chemist is preparing antibiotic solutions. Physical scientists ask questions such as
• How do substances react and form new substances?
• Why does a liquid change to a solid?
• How are force and motion related?

 

1 NOTE

WORD ORIGIN

Read aloud the derivation of the word biology and then ask the following question.

Ask: What are some other sciences with names that end in -ology?

Accept all reasonable responses. Answers may include: zoology, geology, anthropology, entomology, archaeology, meteorology, and psychology.

WORD ORIGIN

biology
from Greek bios, means “life”; and logia, means “study of”

 

11 NOTES

Scientific Inquiry

Ask Questions Hypothesize

Visual Literacy : Figure 2

Analyze Results / Draw Conclusions / Communicate Results

Differentiated Instruction

Differentiated Instruction

Differentiated Instruction

Teacher Demo

Reading Strategy

Differentiated Instruction

Real - World Science

Scientific Inquiry

Point out to students that there is no single scientific method. Rather, there is scientific inquiry. Scientists ask questions about nature and decide on methods that will help them find answers to each one.

Ask Questions
Hypothesize

A properly framed question is one of the first steps in scientific inquiry. The next step in an inquiry is the formation of a hypothesis.

Guiding Questions

Key Concept Check What is scientific inquiry?

Scientific inquiry is a process that uses a set of skills and methods to answer questions or to test ideas about the natural world.

What is a hypothesis?

It is a possible explanation about an observation that can be tested by scientific investigation.

How might a hypothesis be tested?

designing and completing an experiment, making a model, gathering and evaluating evidence, collecting data, and recording observations

Visual Literacy: Figure 2

Ask: What happens if a hypothesis is not supported?

You can modify your hypothesis and repeat the scientific inquiry process.

Have students study the flowchart in Figure 2. It shows a possible sequence of steps involved in formulating and testing a hypothesis.

Analyze Results / Draw Conclusions / Communicate Results

Discuss with students that, after testing the hypothesis, a scientist analyzes the data from the inquiries. From that analysis, a scientist draws conclusions about the validity of the original hypothesis. Scientists then communicate their results with others.

Guiding Questions

If a scientist’s hypothesis predicts a certain outcome of a test and that outcome does not occur, what should the scientist do?

The scientist might modify the hypothesis, continue researching, share results of the study with peers, and repeat the scientific inquiry process.

What is an inference?

An inference is a logical conclusion based on available information or evidence.

What are some examples of how a scientist can communicate results?

write science journal articles, speak at science conferences, exchange information, confer with colleagues

Differentiated Instruction

Writing Hypotheses Tell students to look for clues about what factors can affect plant growth. Have them write down all the possible factors: water, weeding, fertilizer. Then, write hypotheses by incorporating each factor into an if-then statement. For example, “If I give a plant more water, then it will grow taller.”

Differentiated Instruction

The Flow of Scientific Inquiry Have groups create illustrations of methods of scientific inquiry to include headings from the lesson. Then, give this scenario: You walk into a room and try to turn on the lights. They don’t come on. Have students draw and label beneath each heading how they try to solve this problem.

Differentiated Instruction

Hypothesis or Conclusion? Help students identify context clues to differentiate between hypotheses and conclusions. For example, a hypothesis may be an if-then statement, may use future tense, or both. A conclusion may include reference to data and use past tense. Write several statements on the board. As you point to each statement, have students state whether it is a hypothesis or a conclusion and why.

Teacher Demo

2.B.i

Observation or Inference? Review with students the definition of observation as “using one or more of your senses to gather information and take note of what occurs.” Inference is defined as “a logical explanation of an observation that is drawn from prior knowledge or experience.” Display a whole red apple to the class. Ask students to classify these statements as observations or inferences.

1. The apple’s covering is red.

2. The apple is edible.

3. There are seeds inside the apple.

Statement 1 is an observation—it can be seen. Statements 2 and 3 are inferences made from prior knowledge of apples. Could statement 3 become an observation? Cut the apple.

Reading Strategy

Scientific Inquiry In their Science Journals, ask students to write down a difficult problem that they have recently tried to solve in everyday life. Have students compare and contrast the process of a scientific investigation with the process they used to try to solve the problem. Students should ask themselves:
• Did I narrow down my problem to a question, making observations and gathering information? (Ask Questions)
• Did I think of a possible solution and predict an outcome? (Hypothesize and Predict)
• Did I try the solution? (Test Hypothesis)
• Did the solution work? (Analyze Results)
• Did I figure out why the solution worked or failed? (Draw Conclusions)
• Did I let others know that the problem was solved or not? (Communicate Results)

Differentiated Instruction

Retracing the Steps Have student partners write each step of the scientific inquiry process on a separate index card. Have them form a sequence using all of the cards. Next, have them form a new sequence using some or all of the cards. Ask students to describe each sequence in their own words.

Real-World Science

Thinking Like a Scientist Encourage students to pose questions about the world they see—for example, “How do birds fly?” Student questions have probably already been answered. However, they will be thinking like scientists— asking questions. Have students brainstorm questions and design basic investigations to determine answers.

Scientific Inquiry

As scientists study the natural world, they ask questions about what they observe. To find the answers to these questions, they usually use certain skills, or methods. The chart in Figure 2 shows a sequence of the skills that a scientist might use in an investigation. However, it is important to know that, sometimes, not all of these skills are performed in an investigation, or performed in this order.

Scientists practice scientific inquiry—a process that uses a variety of skills and tools to answer questions or to test ideas about the natural world.

(l) Lynn Keddie/Photolibrary, (r) Jose Luis Pelaez, Inc./CORBIS

Figure 2 This flow chart shows steps you or a scientist might use during a scientific investigation.

Visual Check What happens if a hypothesis is not supported?

You can modify your hypothesis and repeat the scientific inquiry process.

 

Ask Questions

Like a scientist, you use scientific inquiry in your life, too. Suppose you decide to plant a vegetable garden. As you plant the vegetable seeds, you water some seeds more than others. Then, you weed part of the garden and mix fertilizer into some of the soil. After a few weeks, you observe that some vegetable plants are growing better than others. An observation is using one or more of your senses to gather information and take note of what occurs.

Observations often are the beginning of the process of inquiry and can lead to questions such as “Why are some plants growing better than others?” As you are making observations and asking questions, you recall from science class that plants need plenty of water and sunlight to grow. Therefore you infer that perhaps some vegetables are receiving more water or sunlight than others and, therefore, are growing better. An inference is a logical explanation of an observation that is drawn from prior knowledge or experience.

Hypothesize

After making observations and inferences, you are ready to develop a hypothesis and investigate why some vegetables are growing better than others. A possible explanation about an observation that can be tested by scientific investigations is a hypothesis.

Your hypothesis might be: Some plants are growing taller and more quickly than others because they are receiving more water and sunlight. Or, your hypothesis might be: The plants that are growing quickly have received fertilizer because fertilizer helps plants grow.
 

Predict

After you state a hypothesis, you might make a prediction to help you test your hypothesis. A prediction is a statement of what will happen next in a sequence of events. For instance, based on your hypotheses, you might predict that if some plants receive more water, sunlight, or fertilizer, then they will grow taller and more quickly.
 

Test Your Hypothesis

When you test a hypothesis, you often are testing your predictions. For example, you might design an experiment to test your hypothesis on the fertilizer. You set up an experiment in which you plant seeds and add fertilizer to only some of them. Your prediction is that the plants that get the fertilizer will grow more quickly. If your prediction is confirmed, it supports your hypothesis. If your prediction is not confirmed, your hypothesis might need revision.
 

Analyze Results

As you are testing your hypothesis, you are probably collecting data about the plants’ rates of growth and how much fertilizer each plant receives. Initially, it might be difficult to recognize patterns and relationships in data. Your next step might be to organize and analyze your data.

You can create graphs, classify information, or make models and calculations. Once data are organized, you more easily can study the data and draw conclusions. Other methods of testing a hypothesis and analyzing results are shown in Figure 2.
 

Draw Conclusions

Now you must decide whether your data do or do not support your hypothesis and then draw conclusions. A conclusion is a summary of the information gained from testing a hypothesis. You might make more inferences when drawing conclusions. If your hypothesis is supported, you can repeat your experiment several times to confirm your results. If your hypothesis is not supported, you can modify it and repeat the scientific inquiry process.
 

Communicate Results

An important step in scientific inquiry is communicating results to others. Professional scientists write scientific articles, speak at conferences, or exchange information on the Internet. This part of scientific inquiry is important because scientists use new information in their research or perform other scientists’ investigations to verify results.
 

1. Key Concept Check What is scientific inquiry?

Scientific inquiry is a process that uses a set of skills and methods to answer questions or to test ideas about the natural world.

 

4 NOTES

Results of Scientific Inquiry

Technology New Materials

Possible Explanations

Differentiated Instruction

Results of Scientific Inquiry

Scientific findings can lead to answers to long-standing questions. They also can result in practical applications.

Guiding Questions

Why might you engage in scientific inquiry?

We do so to find answers to questions about nature.

Key Concept Check What are the results of scientific investigations?

new technology, new materials, and possible explanations of natural phenomena

Technology
New Materials

New technologies and materials often result from scientific research.

Guiding Questions

What is technology?

Technology is the practical use of scientific knowledge, especially for industrial or commercial use.

What is an example of a new material that has resulted from scientific investigation?

Answers will vary, but should show an understanding of how a new material can be useful to people.

Possible Explanations

Scientific inquiry can answer important questions. Such questions can be limited, and specific to a particular time and place, such as “Who committed this crime?” In most cases, scientists’ questions are of a more general nature, such as “What factors are causing global warming?”

Guiding Questions

What questions are asked and answered in many scientific investigations?

Who? What? When? Where? How?

What is an example of a scientific investigation that led to a possible explanation?

Answers will vary, but should show an understanding of the purpose of scientific inquiry.

Differentiated Instruction

Application of Scientific Inquiry Have student groups make poster reports on a technological advance or a new material that resulted from scientific inquiry. In their reports, students should identify the practical question researchers were trying to answer. They should include any relevant steps of scientific inquiry. Have them present their findings to the class.

Results of Scientific Inquiry

Both you and scientists perform scientific inquiry to find answers to questions. There are many outcomes of scientific inquiry, such as technology, materials, and explanations, as shown below.

1. Key Concept Check What are the results of scientific investigations?
 

new technology, new materials, and possible explanations of natural phenomena

Technology
The practical use of scientific knowledge, especially for industrial or commercial use is technology. Televisions, MP3 players, and computers are examples of technology. The C-Leg, shown above, is one of the latest designs of computer-aided limbs. The prosthetic leg has sensors that anticipate the user’s next move, which prevents him or her from stumbling or tripping. In addition, this new technology has several modes that can enable the user to walk, stand for long periods of time, and even ride a bike.
 

New Materials
Another possible outcome of an investigation is a new material. For example, scientists have developed a bone bioceramic. A bioceramic is a natural calcium-phosphate mineral complex that is part of bones and teeth. This synthetic bone mimics natural bone’s structure. Its porous structure allows a type of cell to grow and develop into new bone tissue. The bioceramic can be shaped into implants that are treated with certain cells from the patient’s bone marrow. It then can be implanted into the patient’s body to replace missing bone.
 

Possible Explanations
Many times, scientific investigations answer the questions: who, what, when, where, or how. For example, who left fingerprints at a crime scene? When should fertilizer be applied to plants? What organisms live in rain forests? In 2007, while exploring in Colombia’s tropical rain forests, scientists discovered a new species of poisonous tree frog. The golden frog of Supatá is only 2 cm long.

 

11 NOTES

Scientific Theory and Scientific Laws

Visual Literacy : Table 1

Skepticism in Media Evaluating Scientific Evidence

Science cannot answer all questions . Safety in Science

Differentiated Instruction

Activity

Activity

Fun Fact

Teacher Demo

Teacher Demo

Reading Strategy

Scientific Theory and Scientific Laws

Scientific investigations can lead to the formulation of theories and laws. Use the questions below to help students contrast theories and laws.

Guiding Questions

What is a scientific theory?

It is an explanation of observations or events based on knowledge gained from many observations and investigations.

What is one example of a scientific theory?

Accept all reasonable responses. The cell theory states that all living things are made of cells.

Do you think it’s possible to prove a scientific theory is true?

No, a scientific theory can’t be proved beyond all doubt, but it can be disproved. However, if a tested theory adequately explains observations or events and is not disproved, it is accepted as correct.

What does a scientific law do?

It describes a pattern or event in nature that is always true.

What is one example of a scientific law?

Sample answers include: Law of conservation of mass or the commonly understood law that the Sun will rise again tomorrow.

Reading Check How do scientific theories and scientific laws compare?

A theory explains how and why a particular event occurs. A law simply says that it will occur.

Visual Literacy: Table 1

Have students review Table 1. Then determine how well they have assimilated the information presented by discussing the following questions.

Skepticism in Media
Evaluating Scientific Evidence

It is important to evaluate information presented. It pays to be skeptical about news, especially because the media often reports stories to excite their readers. For research to be valid, it must be conducted in such a way that the investigator’s personal biases do not influence results.

Guiding Questions

What is critical thinking?

It is comparing what you already know about something with new information and then deciding whether you agree with the new information.

Key Concept Check How can a scientist help minimize bias in a scientific investigation?

A blind study will help to prevent bias. Factors that can contribute to bias include poor formation of hypothesis, lack of prior knowledge about the study, researcher expectations of conclusions and de-emphasis of results that do not support that conclusion.

Clinical trials of new drugs are almost always “double-blind” studies. What do you think is meant by that term?

neither the investigators nor the participants in the study know who is getting the drug and who is getting a placebo, or inactive substance

Science cannot answer all questions.
Safety in Science

Briefly discuss with students why topics are testable by science. Safety precautions are important in many kinds of scientific investigations. Brainstorm some potentially dangerous situations and review the appropriate procedures.

Guiding Questions

What safety equipment is essential when working with dangerous chemicals?

safety goggles, an apron, protective gloves, a near source of water, fire extinguisher, fire blanket, eyewash

When are ethical guidelines most often required?

They are most often required in research involving animals or human subjects.

Why are questions about personal opinions, values, beliefs, and feelings beyond science?

They are personal opinion. For instance, science cannot determine which color is prettier. Color preference is subjective.

Differentiated Instruction

Theory or Law? Write several statements on the board. Pair ELL students with English-speaking students and have them quiz each other on whether the statements represent theories or laws. Examples include: The sun rises in the east (law). Objects fall toward Earth (law). Organisms change over time (theory). Birds sing to attract mates (theory).

Activity

Fire Blanket Safety Practice using a fire blanket with students so that they understand how to appropriately use the safety equipment.

Activity

Safety Poster Have student groups create a poster or a bulletin board that emphasizes safe lab procedures including using fire blankets and fire extinguishers. Be sure the products reflect what the safe behavior is and why it should be used in the lab setting.

Fun Fact

How They Work Fire extinguishers cool a burning fire or remove oxygen from the fire’s fuel. Dry chemical extinguishers coat the burning object with powder or foam, and prevent oxygen from reaching the fuel. Carbon dioxide extinguishers cool the fuel and displace oxygen with heavier carbon dioxide. Water extinguishers also cool fire and create a barrier of water between oxygen and the fuel.

Teacher Demo

Cell Theory Evidence Demonstrate how evidence can be gathered to prove the cell theory.

1. Scrape a toothpick against the inside of your cheek, then across a clean microscope slide.

2. Add a drop of stain to the slide. Place a cover slip on the slide and put the slide on the microscope stage.

3. Use the microscope to allow students to observe the cells. Project the image for the class or allow them to take turns viewing into the microscope.

4. Explain that samples taken from every human would all contain cells. This is the basis of the cell theory.

Teacher Demo

Classroom Blind Study Conduct your own blind study. Use three varieties of a common item, such as pudding, popcorn, colored pencils, or tissues. Have students appropriately test the samples without knowing the name and price of each one. Then repeat the study with new samples whose identities are known to the students. Compare the outcome of the two tests. Did bias play a role in students’ selections? Try repeating this test with a product with the brand names and prices switched around in the non-blind part of the test. Will students say they prefer one of the cheaper brands if they think it’s actually the premium brand?

Reading Strategy

Learning Journal Have students use learning journals. Ask students to divide each page into three columns. In the left column, record headings from the text. In the middle column, include summary notes. In the right column, have them include sections of the text and illustrations that helped them understand a concept. Continue the journals throughout the course.

Scientific Theory and Scientific Laws

Scientists often repeat scientific investigations to verify that the results for a hypothesis or a group of hypotheses are correct. This can lead to a scientific theory.

Scientific Theory The everyday meaning of the word theory is an untested idea or an opinion. However, a scientific theory is an explanation of observations or events based on knowledge gained from many observations and investigations.

For example, about 300 years ago, scientists began looking at samples of trees, water, and blood through the first microscopes. They noticed that all of these organisms were made of tinier units, or cells, as shown in Figure 3.

As more scientists observed cells in other organisms, their observations became known as the cell theory. This theory explains that all living things are made of cells. A scientific theory is assumed to be the best explanation of observations unless it is disproved. The cell theory will continue to explain the makeup of all organisms until an organism is discovered that is not made of cells.

Dennis Kunkel Microscopy, Inc./PHOTOTAKE/Alamy

Figure 3 When you view blood using a microscope, you will see that it contains red blood cells.

Scientific Laws Scientific laws are different from societal laws, which are agreements on a set of behaviors. A scientific law describes a pattern or an event in nature that is always true. A scientific theory might explain how and why an event occurs. But a scientific law states only that an event in nature will occur under specific conditions.

For example, the law of conservation of mass states that the mass of materials will be the same before and after a chemical reaction. This scientific law does not explain why this occurs—only that it will occur. Table 1 compares a scientific theory and a scientific law.

Table 1 Comparing Scientific Theory and Scientific Law

 

Skepticism in Media

When you see scientific issues in the media, such as newspapers, radio, television, and magazines, it is important to be skeptical. When you are skeptical, you question information that you read or hear, or events you observe.
Is the information truthful?
Is it accurate?
Is the source reliable?
It also is important that you question statements made by people outside their area of expertise, and claims that are based on vague statements.

Evaluating Scientific Evidence

An important skill in scientific inquiry is critical thinking. Critical thinking is comparing what you already know with the information you are given in order to decide whether you agree with it. Identifying and minimizing bias also is important when conducting scientific inquiry. To minimize bias in an investigation, sampling, repetition, and blind studies can be helpful, as shown in Figure 4.

1. Key Concept Check How can a scientist minimize bias in a scientific investigation?
 

A blind study will help to prevent bias. Factors that can contribute to bias include: poor formation of hypothesis, lack of prior knowledge about the study, researcher expectations of conclusions and de-emphasis of results that do not support that conclusion.

Figure 4 Scientists use different methods to help prevent bias.

 

Science cannot answer all questions.

You might think that any question can be answered through a scientific investigation. But there are some questions that science cannot answer, such as the one posed in Figure 5.

Questions about personal opinions, values, beliefs, and feelings cannot be answered scientifically. However, some people use scientific evidence to try to strengthen their claims about these topics.
 

Plush Studios/Getty Images

Figure 5 Science cannot answer questions based on opinions or feelings, such as which paint color is the prettiest.

 

Safety in Science

Scientists follow safety procedures when they conduct investigations. You too should follow safety procedures when you do any experiments. You should wear appropriate safety equipment and listen to your teacher’s instructions. You should also have proper safety equipment easily accessible in the lab in case an accident would occur. For example, fire extinguishers and fire blankets are necessary safety equipment when using open flames or flammable materials. Also, you should learn to recognize potential hazards and to know the meaning of safety symbols. Read more about science laboratory safety in the Science Skill Handbook.
 

Ethics are especially important when using living things during investigations. Animals should be treated properly. Scientists also should tell research participants about the potential risks and benefits of the research. Anyone can refuse to participate in scientific research.

 

1 NOTE

ACADEMIC VOCABULARY

Use caution when discussing ethical treatment of animals as students may feel strongly, giving rise to debate and possible hurt feelings.

ACADEMIC VOCABULARY

ethics
(noun) rules of conduct or moral principles

 

Lesson Assessment

Use Vocabulary

1. Explain the relationship between observations and hypotheses.

An observation in nature often leads to a testable hypothesis that explains how or why the observation occurred.

2. Use the terms technology, scientific law, and scientific theory in complete sentences.

Sample answer: The new video game has the latest, most amazing technology. The change of season is an example of a scientific law in action. One basic scientific theory is that all living things are made up of cells.

3. Contrast inference and prediction.

An inference is a logical explanation of an observation that is drawn from prior knowledge or experience. A prediction is a statement of what will happen next in a sequence of events.

4. Compare and contrast critical thinking and inference.

Both are decision-making skills. An inference is a logical explanation of an observation that is drawn from prior knowledge or experience. Critical thinking is comparing what you already know with the information you are given in order to decide whether you agree with it.

Understand Key Concepts

5. Which should NOT be part of scientific inquiry?

      A. bias

      B. analysis

      C. hypothesis

      D. testing

6. Describe four real-life examples of the results of scientific investigations.

Sample answers: artificial limbs, vaccines, pharmaceutical drugs, airplanes, spacecraft, synthetic textiles, and the discovery of all the planets and their moons

7. Discuss four ways a scientist can reduce bias in scientific investigations.

A scientist can use a blind study, sampling, and repetition and not allow prior knowledge to influence the interpretation of test results.

8. Which is NOT a source of bias?

      A. accurate records

      B. equipment choice

      C. funding source

      D. hypothesis formation

Interpret Graphics

9. Draw a graphic organizer like the one below. In each oval, list an example of how to test a 
    hypothesis using scientific inquiry.

design an experiment, make a model, gather and evaluate evidence, and collect data/record observations

Critical Thinking

10. Suggest Why do you think people believe some theories even if they are not supported by
       credible evidence?

Sample answers might include: People might not understand the process of scientific inquiry; they might think a common theory is supported by valid evidence, even though in reality it is not. They also might believe common theories because, for personal reasons, they want to believe in what the theory is saying.

11. Evaluate In a magazine, you read that two scientific investigations attempted to answer the
       same question. However, the two teams of scientists came to opposite conclusions. How do you
       decide which investigation was valid?

Sample answers might include: To decide which investigation is valid, you use critical thinking skills to examine the information you are given. You should be skeptical of investigations that show signs of bias. You should examine the investigations for correct use of the skills of scientific inquiry and laboratory procedures.

12. Explain What would be the next step in the scientific inquiry process below?


 

Test hypothesis, which includes design an experiment, make a model, gather and evaluate evidence, and collect data/record observations.

13. Select a science career that uses technology. Explain how that career would be different if the
       technology had not been invented.

Accept all reasonable answers. Sample answer: A computer programmer uses technology and writes programs to make technology usable and available to more people. If computers did not exist, computer programmers would not exist. All processes and systems that use computers would not exist or would be manual processes.

14. What process do scientists use to perform scientific investigations? List a possible sequence of 
       steps in a scientific inquiry and explain your reasoning

Scientists use a process called the scientific method. Steps include: gather information, hypothesize and predict, test hypothesis, analyze results, draw conclusions, communicate results

15. What next step of scientific methods might these marine biologists perform?

Images & Stories/Alamy

The biologists might continue to collect more data or might begin to organize and analyze their data.

16. A student was using a lit match during a laboratory investigation and did not extinguish it 
      properly when it was disposed of. The match caused a fire in the trash can.
      What procedures should be followed to put out the fire?
      What procedures should be followed if a person's hair catches fire?

A student should not try to put out a fire. A teacher should be notified and students should leave the area if a fire occurs. The teacher will then determine if he or she is able to put out the fire with a fire extinguisher and call the fire department. If a person is on fire, a fire blanket should be used as the person drops to the ground and rolls to put out the flames.

Writing in Science

17. Write a five-sentence paragraph that includes examples of how bias can be intentional or
       unintentional and how scientists can reduce bias. Be sure to include topic and concluding
       sentences in your paragraph.

Students’ paragraphs should contain facts from the section and they should include a topic sentence and a concluding sentence.

1st Day of school Homework.Write 5 sentences or more about a career in science. Use the links below to help you. Do not copy and paste, re-write any information in your own words.

 

Cool Careers in Science
Explore Careers in Science

 

Welcome back to school!

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