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How Science Works
Main Idea Science can be used to learn about ancient cultures.
Scientific Problem Solving
Main Idea Solving any problem scientifically involves several steps.
Science and Technology Make the following Foldable to compare and contrast science and technology.
Fold one sheet of paper lengthwise.
Unfold and draw overlapping ovals. Cut the top sheet along the folds.
Label the ovals as shown.
To create a Venn Diagram, identify and list the unique aspects of science on the left side, the distinct characteristics of technology on the right side, and the shared features of both in the center.
Excavating tools and artifacts from past human civilizations is a meticulous process that requires patience and precision It is crucial to handle these remains delicately to prevent any damage or destruction during their extraction from the soil.
Try to excavate a cookie without destroying the treasures within.
WARNING: Never eat or drink in the science lab, and never use lab glassware as a food or drink container.
1 Obtain an oatmeal cookie with raisins and walnuts from your teacher.
2 Place the cookie on a large paper towel.
3 Use a biology probe to remove the raisins and walnuts from the cookie without damaging either one
4 Give all pieces of the excavated cookie to your teacher for disposal.
5 Wash your hands with soap and water when you have finished
Probing a cookie can be likened to the process of excavating ancient life from Earth's crust, as both activities involve careful examination and extraction of hidden elements Just as archaeologists meticulously remove bones and artifacts to uncover the history of past civilizations, probing a cookie allows us to discover its internal structure and ingredients This comparison highlights the importance of critical thinking and analytical skills in both scientific exploration and culinary analysis, emphasizing the value of uncovering layers of information to gain a deeper understanding of our world.
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Pascal Goetgheluck/Science Photo Library/Photo Researchers Pascal Goetgheluck/Science Photo Library/Photo Researchers 55
6 A CHAPTER 1 The Nature of Science
Apply It! Now that you have skimmed the chapter, write a short paragraph describing one thing you want to learn from this chapter.
Learn It! If you know what to expect before reading, it will be easier to understand ideas and relationships presented in the text.
Follow these steps to preview your reading assignments.
Practice It! Take some time to preview this chapter. Skim all the main headings and subheadings With a partner, discuss your answers to these questions.
• Which part of this chapter looks most interesting to you?
• Are there any words in the headings that are unfamiliar to you?
• Choose one of the lesson review questions to discuss with a partner.
1.Look at the title and any illustrations that are included.
2.Read the headings, subheadings, and anything in bold letters.
3.Skim over the passage to see how it is organized Is it divided into many parts?
4.Look at the graphics—pictures, maps, or diagrams Read their titles, labels, and captions.
5.Set a purpose for your reading Are you reading to learn some- thing new? Are you reading to find specific information?
Before You Read Statement After You Read
1 Archaeology is the study of Earth processes.
2 Geology is a branch of science that studies the tools and other cultural remains of humans.
3 Many archaeological sites are found by accident.
4 Technology is the use of knowledge gained through science to make new products or tools.
5 Step-by-step procedures of scientific problem solving are called scientific laws.
6 The steps in a scientific approach can vary and aren’t always done in the same order.
7 Recognizing a problem is seldom necessary when using a scientific approach.
8 A hypothesis is a statement that can be tested.
9 Variables are factors in an experiment that always stay the same.
10 It’s important to keep everything the same in an experiment except for the variable you are testing.
As you preview this chapter,be sure to scan the illustrations, tables, and graphs Skim the captions.
Use this to focus on the main ideas as you read the chapter.
Before you readthe chapter, respond to the statements below on your worksheet or on a numbered sheet of paper.
• Write an A if you agree with the statement.
• Write a D if you disagree with the statement.
After you readthe chapter, look back to this page to see if you’ve changed your mind about any of the statements.
• If any of your answers changed, explain why.
• Change any false statements into true statements.
• Use your revised statements as a study guide.
Print out a worksheet of this page at green.msscience.com
6 CHAPTER 1 The Nature of Science
On a Friday morning, Ms Garcia's science class at York Middle School was buzzing with excitement as students prepared for a special field trip to observe the construction of a new gymnasium Among them, group 4—comprising Ben, Emily, Maria, and Juan—eagerly watched construction equipment, including bulldozers and trucks, arrive at the site Armed with pencils and notebooks, the students ventured out to witness the impressive machinery in action, as massive shovels relocated hundreds of kilograms of dirt.
In an unexpected turn of events, the power-shovel operator halted the massive scoop mid-air, intrigued by what lay beneath Climbing down from his elevated position, he summoned fellow workers to gather around the excavation site Together, they peered into the pit, captivated by the mystery unfolding before them.
Ms Garcia and her students to come a little closer Everyone was surprised at what they saw A piece of broken pottery was stick- ing out from the loosened soil.
■ Explain the science of archaeology.
■ Compare and contrast science and technology.
Science and technology are impor- tant parts of your everyday world.
Review Vocabulary artifact: object of historical inter- est produced by humans, such as a tool or weapon
Figure 1 Construction efforts sometimes unearth prehistoric sites.
Charles Gupton/Stock Boston/PictureQuest
During an excavation, one worker proposed that the discovered pottery could be just one of many discarded items buried prior to the school's construction However, another worker expressed skepticism, suggesting that the pottery might actually be an ancient artifact, similar to the example depicted in Figure 2.
Nonetheless, a decision was made to stop the excavation, at least for the moment.
In the classroom, students eagerly discussed their discovery, recognizing it as a genuine scientific experience They understood that science is fundamentally about exploring and comprehending the world around them.
Ms Garcia emphasized to the students that the recently discovered pottery could potentially be a modern discard rather than an ancient artifact To clarify its significance, the school's principal consulted a local college archaeologist for expert analysis.
Scientists, like Dr Lum, specialize in studying the cultural remains of ancient humans, known as artifacts These artifacts can include tools, weapons, rock drawings, buildings, and pottery On Monday, Dr Lum will visit the school to examine the pottery found there.
Ms Garcia encouraged her students to delve into the local history to understand the origins of pottery from ancient cultures in their area Ben and his group promptly started their research, while Maria suggested taking notes on their discoveries for comparison with Dr Lum's insights.
Monday The others in the group agreed and put their science notebooks into their backpacks before heading to the library.
Archaeologists work in the field to gather data.
Figure 2 Much can be learned about ancient cul- tures from materials they left behind.
Topic: Artifacts and Human History
Visit for Web links to information about how artifacts provide clues about human behavior and history.
In this activity, select a human artifact such as a tool, art piece, or waste material, and provide three specific examples along with their discovery locations For instance, the ancient stone tool found at Olduvai Gorge in Tanzania, the intricate pottery discovered at the archaeological site of Çatalhöyük in Turkey, and the prehistoric cave paintings located in Lascaux, France Analyzing these artifacts reveals significant insights into the lives of the humans who created them, including their technological advancements, artistic expression, and cultural practices.
Archaeologists study pottery and other items to learn more about ancient humans.
(l)Coco McCoy from Rainbow, (r)Stephen J Krasemann/Photo Researchers
8 CHAPTER 1 The Nature of Science
At the library, Juan used an encyclopedia to begin his research.
Archaeology is a scientific discipline that examines human tools and cultural artifacts It is divided into two main branches: one investigates prehistoric societies prior to written history, while the other focuses on civilizations that emerged after the advent of writing Remarkably, archaeology encompasses a timeline exceeding 3 million years, with evidence suggesting that the earliest human ancestors appeared around 3.5 million years ago.
What are the two major branches of archaeology?
The students explored the history of their area, uncovering that scientists believe the first people arrived in North America from Asia around 12,000 years ago, with migrations occurring over thousands of years Emily and Maria learned that their city was settled approximately 2,000 years ago After gathering information from various sources, they took notes and decided to jot down questions about pottery and archaeology Excited to compare their findings with Dr Lum's insights on Monday, the group left the library with anticipation.
One branch of archaeology studies the cultural remains of people who lived before history was written.
Figure 3 Archaeologists study artifacts of ancient people like those from ancient Egypt or like those who came to North America about 12,000 years ago.
PacificOceanBering StraitSIBERIA
Dr Lum arrived before nine o'clock, and when the bell rang, Emily eagerly raised her hand, hoping to be the first to inquire about the pottery.
Dr Lum said she wanted to give the students some back- ground information and then she would answer their questions.
Dr Lum emphasized the significance of preserving prehistoric sites for both current and future generations She noted that many archaeological discoveries, such as the potential site located on school grounds, often occur by chance Before any construction can proceed, further scientific investigation is essential.
Minerals
Main Idea Minerals are formed by natural processes, are inorganic, have definite chemical compositions, and are crystalline solids.
Mineral Identification
Main Idea Each mineral is identified by its physical properties.
Uses of Minerals
Main Idea Minerals are important because some are rare, have special properties, or contain materials that have many uses.
Diamonds, renowned for their beauty and expertly cut by gemologists, are naturally formed deep within the Earth, meeting the criteria of a mineral by occurring in nature In contrast, while human-made diamonds are useful in various industrial applications, they do not qualify as minerals.
Write two questions you would ask a gemologist about the min- erals that he or she works with.
Minerals Make the following Foldable to help you better understand minerals.
Fold a vertical sheet of note- book paper from side to side.
Cut along every third line of only the top layer to form tabs.
Label each tab with a question.
Before diving into the chapter, formulate questions about minerals and jot them down at the top of the tabs As you progress through the reading, continue to add more questions and provide answers beneath the relevant tabs This interactive approach enhances comprehension and retention of the material.
1 Use a magnifying lens to observe a quartz crystal, salt grains, and samples of sandstone, granite, calcite, mica, and schist (SHIHST).
2 Draw a sketch of each sample.
3 Infer which samples are made of one type of material and should be classified as minerals.
4 Infer which samples should be classified as rocks.
In your Science Journal, critically analyze the minerals and rocks you studied by creating two distinct lists: one for the characteristics of minerals and another for the properties of rocks Then, compare and contrast your findings to highlight the differences and similarities between these geological materials.
Rocks often consist of multiple materials, with many being composed of various crystals primarily from the same mineral.
A mineral, however, will appear more like a pure substance and will tend to look the same throughout Can you tell a rock from a mineral?
Preview this chapter’s content and activities at green.msscience.com
Apply It! Make a vocabulary bookmark with a strip of paper As you read, keep track of words you do not know or want to learn more about.
Learn It! What should you do if you find a word you don’t know or understand? Here are some suggested strategies:
Practice It! Look at the word natural in the following passage See how context clues can help you understand its meaning.
1.Use context clues (from the sentence or the paragraph) to help you define it.
2.Look for prefixes, suffixes, or root words that you already know.
3.Write it down and ask for help with the meaning.
5.Look it up in the glossary or a dictionary.
All minerals are created through natural processes that take place on or within the Earth without human intervention For instance, halite, a mineral, is formed from the natural evaporation of seawater, while salt produced through evaporation in laboratory settings does not qualify as a mineral.
Context Clue describes types of processes
Context Clue occur with no input from humans
Context Clue examples of two substances to compare and contrast
Use this to focus on the main ideas as you read the chapter.
Before you readthe chapter, respond to the statements below on your worksheet or on a numbered sheet of paper.
• Write an A if you agree with the statement.
• Write a D if you disagree with the statement.
After you readthe chapter, look back to this page to see if you’ve changed your mind about any of the statements.
• If any of your answers changed, explain why.
• Change any false statements into true statements.
• Use your revised statements as a study guide.
Before You Read Statement After You Read
1 All minerals are solids, but not all solids are minerals.
2 The word crystallinemeans that atoms are arranged in a repeating pattern.
3 The two most abundant elements in Earth’s crust are silicon and carbon.
4 Like vitamins, minerals are organic substances, which means they contain carbon.
5 Color is always the best physical property to use when attempting to identify minerals.
6 A mineral’s hardness is a measure of how easily it can be scratched.
7 Most gems or gemstones are special varieties of particular minerals.
8 Synthetic, or human-made, diamonds are minerals.
9 A mineral or rock is called an ore only if it con- tains a substance that can be mined for a profit.
Print out a worksheet of this page at green.msscience.com
Read a paragraph containing a vocabulary word from beginning to end Then,go back to determine the meaning ofthe word.
Minerals play a crucial role in our daily lives, as they are essential components of numerous products we encounter regularly From ceramics and metals to certain paper items, many everyday objects are derived from or incorporate minerals, highlighting their significance in our daily routines.
Minerals are essential to our everyday lives, as seen in common items like metal bicycle racks, bricks, and window glass Defined as naturally occurring, inorganic solids with a specific chemical composition and orderly atomic arrangement, minerals play a crucial role in various materials Earth is home to approximately 4,000 different minerals, all of which exhibit these fundamental characteristics.
Minerals are naturally occurring substances formed through processes that take place on or within the Earth, without human intervention An example is halite, which is created by the natural evaporation of seawater, unlike salt produced in laboratories Additionally, minerals are inorganic, meaning they are not derived from living organisms Each mineral possesses a specific chemical composition, such as halite's NaCl, which contributes to its unique flavor Furthermore, minerals are characterized as crystalline solids, possessing a definite volume and shape, distinguishing them from gases and liquids, which lack these properties While all minerals are solids, not all solids qualify as minerals.
Crystalline structures are characterized by atoms organized in a repeating pattern, such as the layered arrangement found in graphite In contrast, opal does not qualify as a mineral in the strictest sense, as its atomic arrangement lacks a definite and repeating pattern, despite being a naturally occurring inorganic solid.
■ Describe characteristics that all minerals share.
You use minerals and products made from them every day.
Review Vocabulary atoms: tiny particles that make up matter; composed of protons, electrons, and neutrons
Figure 1 You probably use minerals or materials made from minerals every day without think- ing about it.
Infer How many objects in this pic- ture might be made from minerals?
Do you have a favorite mineral sample or gemstone? If so, perhaps it contains well-formed crystals A crystal is a solid in which the atoms are arranged in orderly, repeating patterns.
The smooth, flat surfaces of crystals provide clear evidence of their orderly atomic arrangement Crystals are categorized into crystal systems, which consist of groups sharing similar atomic structures and corresponding external shapes.
Not all mineral crystals exhibit smooth surfaces and regular shapes; for instance, while clear quartz crystals display a distinct hexagonal form, rose quartz lacks visible crystal shape due to its growth in confined spaces Both types have atoms arranged in repeating patterns, but the conditions of their formation significantly influence their external appearance The six-sided structure of clear quartz is prominent in some samples, and minerals are classified into six major crystal systems based on their structures, with quartz belonging to the hexagonal system.
Crystals form by many processes Next, you’ll learn about two of these processes—crystals that form from magma and crystals that form from solutions of salts.
Figure 2 More than 200 years ago, the smooth, flat surfaces on crystals led scientists to infer that minerals had an orderly structure inside.
Even though this rose quartz looks uneven on the outside, its atoms have an orderly arrangement on the inside.
The well-formed crystal shapes exhibited by these clear quartz crystals suggest an orderly structure.
Using a magnifying lens, examine grains of common table salt placed on a dark sheet of construction paper, and sketch the unique shape of a salt grain Remember, do not taste or eat any mineral samples, and keep your hands away from your face for safety.
2 Compare the shapes of the salt crystals with the shapes of crystals shown in Figure 3.
1 Which characteristics do all the grains have in common?
2 Research another mineral with the same crystal sys- tem as salt What is this crystal system called?
(inset)John R Foster/Photo Researchers, (l)Mark A Schneider/Visuals Unlimited
A crystal’s shape depends on how its atoms are arranged
Crystal shapes can be organized into groups known as crys- tal systems—shown here in 3-D with geometric models
(in blue).Knowing a mineral’s crystal system helps researchers understand its atomic structure and physical properties
Tetragonal crystals, such as zircon, are characterized by having one principal dimension that is either longer or shorter than the other two, distinguishing them from cubic crystals.
The triclinic crystal system is characterized by minerals that display minimal symmetry, exemplified by rhodonite In triclinic crystals, all dimensions are unequal, and the angles at which crystal surfaces intersect are oblique.
MONOCLINIC (mah nuh KLIH nihk) Minerals in the monoclinic system, such as orthoclase,also exhibit unequal dimensions in their crystal structure
Only one right angle forms where crystal surfaces meet.The other angles are oblique,which means they don’t form 90º angles where they intersect
HEXAGONAL (hek SA guh nul) In hexag- onal crystals, horizontal distances between opposite crystal surfaces are equal.These crystal surfaces intersect to form 60º or
120º angles.The vertical length is longer or shorter than the horizontal lengths
CUBIC Fluorite is an example of a mineral that forms cubic crystals Minerals in the cubic crystal system are equal in size along all three principal dimensions
Minerals with orthorhombic structure, such as barite, have dimensions that are unequal in length, resulting in crystals with a brick-like shape
(tr)Mark A Schneider/Visuals Unlimited, (cl)A.J Copley/Visuals Unlimited, (cr bl)Harry Taylor/DK Images, (bc)Mark A Schneider/Photo Researchers, (br)Mark A Schneider/Visuals Unlimited
Crystals are formed from magma through natural processes, where hot melted rock cools either at the Earth's surface or beneath it As magma cools, its atoms lose heat energy and come together to create compounds, arranging themselves into orderly, repeating patterns The specific minerals that develop depend on the types and quantities of elements present in the magma, while the size of the resulting crystals is influenced by the cooling rate of the magma.
When magma cools slowly, the crystals that form are gener- ally large enough to see with the unaided eye, as shown in