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4 and Nonmetals and 4 Metalloids

Objectives After this lesson, students will be able to Reading Preview K.3.4.1 Describe the properties of Key Concepts What Are the Properties of ? nonmetals. • What are the properties of 1. Break off a piece of charcoal and roll it between your fingers. K.3.4.2 Tell how metalloids are useful. nonmetals? Record your observations. • How are the metalloids useful? 2. Rub the charcoal on a piece of . Describe what happens. 3. Strike the charcoal sharply with the blunt end of a fork. Target Reading Skill Key Terms Describe what happens. • Using Prior Knowledge Explain that using 4. When you are finished with your investigation, return the • diatomic prior knowledge helps students connect charcoal to your teacher and wash your hands. • noble what they already know to what they are • Think It Over about to read. Classifying Charcoal is a form of the element . Would Target Reading Skill you classify carbon as a or a nonmetal? Use your Answers observations from this activity to explain your answer. Sample answers: Using Prior Knowledge Before you read, write what you know What You Know about the properties of nonmetals 1. Nonmetals are not shiny. and metalloids in a graphic Life on depends on nonmetals. All are made 2. organizer like the one below. As from compounds of carbon. The air you and other living things Nonmetals are not magnetic. you read, write what you learn. What You Learned breathe contains mostly and . , a key compound in living cells, consists of and oxygen. Yet, 1. Nonmetals are dull and brittle. What You Know while many compounds made with nonmetals are essential to 2. Metalloids have characteristics of 1. Nonmetals are not shiny. life, some nonmetals themselves are poisonous and highly and nonmetals. 2. reactive. Still others are completely unreactive. Compared to Teaching Resources metals, nonmetals have a much wider variety of properties. However, nonmetals do have several properties in common. • Transparency K28 What You Learned 1. 2. Preteach Build Background Knowledge L2 Experience With Ask: What do you know about chlorine? (Sample answer: Chemical used in swimming pools, part of ) Encourage students to These bears, the grass build on their experiences with chlorine in behind them, and all life on Earth is based on swimming pools and share their carbon, a nonmetal. observations. Point out the position of chlorine in the . Invite students to share any knowledge they may have about elements near chlorine.

students that the charcoal has been mixed with clay to keep its shape. Skills Focus Classifying L1 Expected Outcome The charcoal breaks activated charcoal, paper, fork easily, rubs off on fingers and paper, and Time 5 minutes shatters when hit with a fork. Tips Activated charcoal is available where Think It Over Sample answer: Carbon aquarium supplies are sold. You may is brittle, dull, not malleable, and not substitute charcoal briquettes, but tell lustrous. Carbon is not a metal. 0072_sx09_K_te_Ch03.fm Page 99 Sunday, January 13, 2008 1:38 PM

FIGURE 20 Instruct Physical Properties of Nonmetals Nonmetals have properties Properties of that are the opposite of metals. Comparing and Contrasting Nonmetals Contrast the properties of these nonmetals with those of metals. Teach Key Concepts L2 Contrasting Nonmetals and Metals

The filling this Focus Tell students that nonmetals are most is a gas at room often described as anything that is not a metal. . Teach List the properties of metals crumbles discussed in Metals. Then, list properties of into a powder. nonmetals, opposite the corresponding metal property. Ask: Are nonmetals good Nonmetals are good insulators. Carbon conductors of heat and electricity? (No) In compounds are found what state are most nonmetals found at in the insulating room temperature? (Most are , some are these wires. , only one is a liquid.) Explain that most nonmetals are brittle. Ask: What properties of metals are the opposite of brittle? (Malleable and ductile) Properties of Nonmetals Apply Ask: What properties of oxygen make it a nonmetal? (Sample answer: It is A nonmetal is an element that lacks most of the properties of a a gas at room temperature and a poor metal. Most nonmetals are poor conductors of electricity and conductor of electricity and heat.) learning heat and are reactive with other elements. Solid nonmetals modality: verbal are dull and brittle. Look at the periodic table in Section 2. All of the elements in -tinted boxes are nonmetals. Many of Independent Practice L2 the nonmetals are common elements on Earth. Teaching Resources Physical Properties Ten of the 16 nonmetals are gases at • Guided Reading and Study Worksheet: room temperature. The air you breathe is mostly a of Nonmetals and Metalloids two nonmetals, nitrogen (N) and oxygen (O). Other nonmetal elements, such as carbon (C), (I), and sulfur (S), are sol- Student Edition on Audio CD

ids at room temperature. (Br) is the only nonmetal that is liquid at room temperature. Look at examples of nonmetals in Figure 20. In general, the physical properties of nonmetals are the opposite of those of the metals. Solid nonmetals are dull, meaning not shiny, and brit- tle, meaning not malleable or ductile. If you hit most solid non- metals with a , they break or crumble into a powder. Nonmetals usually have lower than metals. And non- metals are also poor conductors of heat and electricity.

Differentiated Instruction English Language Learners/ English synonyms or native words. L2 Beginning L1 learning modality: visual Monitor Progress Comprehension: Key Concept Rewrite Writing Instruct students to write down one English Language Learners/ the boldfaced sentences on this page as a characteristic that most nonmetals have. Intermediate L2 list of nonmetal properties. Have students Comprehension: Key Concept Have Answer construct a cluster diagram with students complete the activity at left, but Figure 20 Sulfur is brittle, helium is a gas, “Properties of Nonmetals” in the center do not allow them to use native words. and do not conduct electricity. and each property connected to it by a line. learning modality: visual Metals are bendable, good conductors of Allow students to list properties using electricity, and usually solid at room temperature. 0072_sx09_K_te_Ch03.fm Page 100 Sunday, January 13, 2008 1:38 PM

Use Visuals: Figure 21 L2 Chemical Properties Most nonmetals are reac- and tive, so they readily form compounds. In fact, fluo- rine (F) is the most reactive element known. Yet, Focus Remind students that metals react 18 elements hardly ever form compounds. with other elements by losing electrons and of nonmetals usually gain or share elec- nonmetals react by gaining or sharing trons when they react with other atoms. When non- electrons. metals and metals react, electrons move from the Teach Direct students to look at Figure 21. metal atoms to the nonmetal atoms, as shown by the Ask: Which element will gain an ? formation of , shown in Figure 21. Another (Chlorine) Which element will lose an example is —a compound made of and electron? () oxygen (Fe2O3). It’s the reddish, flaky coating you Apply Explain that the reactivity of Sodium Chlorine might see on an old piece of or an iron . Many nonmetals can also form compounds with elements depends on electrons. Ask: Why do – e other nonmetals. The atoms share electrons and the nonmetals in Group 18 rarely react become bonded together into . with other elements to form compounds? (They do not readily lose or share electrons.) In which portion of the periodic table do you find nonmetals? learning modality: visual FIGURE 21 Reactions of Nonmetals The table salt on a pretzel is mined from Families of Nonmetals deposits found on Earth. The same Families of Nonmetals compound can also be formed from a Look again at the periodic table. Notice that only reaction between the metal sodium and Group 18 contains elements that are all nonmetals. Teach Key Concepts L2 the nonmetal chlorine. In Groups 14 through 17, there is a mix of nonmet- Nonmetal Groups als and other kinds of elements. Focus Point out that Group 18 is the one The Carbon Family Each element in the that consists only of nonmetals. family has atoms that can gain, lose, or share four However, nonmetals in mixed groups do electrons when reacting with other elements. In share similar properties with the metals in Group 14, only carbon is a nonmetal. What makes 14 carbon especially important is its role in the chemis- their group. 6 Teach Begin a table on the board with C try of life. Compounds made of molecules contain- ing long chains of carbon atoms are found in all properties of nonmetals as you did with Carbon living things. metals. Again, keep track of the properties of 14 Most of the fuels that are burned to energy each nonmetal family as students study Si contain carbon. Coal, for example, is mostly the ele- them. Record the properties of that group, 32 ment carbon. Gasoline is made from crude oil, a including the number of electrons lost when mixture of with chains of 5 to 50 reacting with other elements. Also include Ge or more carbon atoms in their molecules. examples of each. 50 Apply Ask: What property do elements in Sn mixed groups share? (They all gain, lose, IGURE 82 F 22 or share the same number of electrons.) Carbon learning modality: visual Pb Charcoal is one form of carbon, the only nonmetal in Group 14.

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The Nitrogen Family Group 15, the nitrogen family, con- Help Students Read L2 tains two nonmetals, nitrogen and . These non- Vocabulary: Word Part Analysis Write metals usually gain or share three electrons when reacting with the word diatomic on the board and ask: other elements. To introduce yourself to nitrogen, take a deep What is the root word of this word? () breath. The atmosphere is almost 80 percent nitrogen gas (N2). Explain that the prefix di- means “two” or Nitrogen does not readily react with other elements, so you “double.” The suffix -ic means “of,” or breathe out as much nitrogen as you breathe in. 15 “pertaining to.” Say that this suffix changes a Nitrogen is an example of an element that occurs in 7 noun to an adjective. Ask: Since you know in the form of diatomic molecules, as N2. A N Nitrogen that an atom is a particle of matter, what consists of two atoms. In this form, nitrogen is not very reac- does “diatomic molecule” mean? (A 15 tive. Although living things need nitrogen, most of them are molecule formed of two atoms) unable to use nitrogen from the air. However, certain kinds P of can use this nitrogen to form compounds. This Phosphorus process is called nitrogen fixation. Plants can then take up 33 As L2 these nitrogen compounds formed in the by the bacteria. Farmers also add nitrogen compounds to the soil in the form 51 of fertilizers. Like all animals, you get the nitrogen you need Sb Reading Fertilizer Bags from the food you eat—from plants, or from animals that ate plants. Materials labels from various types of 83 fertilizers Phosphorus is the other nonmetal in the nitrogen family. Bi Phosphorus is much more reactive than nitrogen, so phospho- Time 15 minutes rus in nature is always found in compounds. A compound con- Focus Tell students that nitrogen and taining phosphorus is used to make matches, because it can phosphorus are two of the key ingredients react with oxygen in the air. in fertilizers. Teach Have students find the guaranteed FIGURE 23 analysis of chemicals on the fertilizer label. The Nitrogen Family Ask: In what form is the nitrogen present in Nitrogen and phosphorus are grouped the fertilizer? (Sample answer: and in the same family of the periodic table, Group 15. Making Generalizations compounds) In what form is the How do atoms of both these elements Nitrogen is a key phosphorus? (Sample answer: ) change when they react? ingredient of fertilizers. Apply Ask: Why aren’t nitrogen and phosphorus present as pure elements in the fertilizer? (As part of a compound, nitrogen and phosphorus are more stable and in a form that plants can easily use.) learning modality: verbal

Match heads contain a highly reactive phosphorus compound that ignites easily.

Differentiated Instruction Monitor Progress L2 Special Needs L3 boxes represent? (Green indicates a Oral Presentation Have students give the Interpreting Visuals Have students look nonmetal, yellow is a metalloid, and blue is a number of electrons that elements in the at the column of symbols for the Group 15 metal.) Then have students create a chart carbon family and elements in the nitrogen elements shown in Figure 23. Then have with the headings Metal, Nonmetal, and family usually lose, gain, or share. them locate the same column in the large Metalloid. Direct students to write in the periodic table shown earlier and compare chart the names of the Group 15 elements Answers the two. Point out that, except for atomic that fit into each category. Have students Figure 23 Both gain or share three , both illustrations list the same identify and circle the name of the only electrons. information for each element in the group. element in the group that is a gas. To the right of the metalloids Ask: What do the different colors of the (Nitrogen) learning modality: visual 0072_sx09_K_te_Ch03.fm Page 102 Sunday, January 13, 2008 1:38 PM

The Oxygen Family Group 16, the oxygen family, contains three nonmetals—oxygen, sulfur, and . These ele- L2 ments usually gain or share two electrons when reacting with Show Me the Oxygen other elements. Finding Nonmetals How can you test for the You are using oxygen right now. With every breath, oxygen presence of oxygen? Materials none travels into your lungs. There, it is absorbed into your - 1. Pour about a stream, which distributes it all over your body. You could not 3-cm depth of Time 15 minutes live without a steady supply of oxygen. Like nitrogen, the oxy- (H2O2) Focus Tell students that nonmetals have into a test tube. gen you breathe is a diatomic molecule (O2). In addition, oxy- many different uses. 2. Add a pea-sized amount of gen sometimes forms a triatomic (three-atom) molecule, Teach Invite student groups to look for dioxide which is called (O3). Ozone collects in a layer in the (MnO ) to the test tube. upper atmosphere, where it screens out harmful radiation nonmetals in the classroom and around the 2 3. Observe the test tube for from the . However, ozone is a dangerous pollutant at school building and grounds. Have them list about 1 minute. ground level because it is highly reactive. the nonmetals they observe and describe 4. When instructed by Because oxygen is highly reactive, it can combine with their uses. When students return to the your teacher, set a almost every other element. It also is the most abundant ele- classroom, make a class list of the observed wooden splint on fire. ment in Earth’s crust and the second-most abundant element nonmetals. Then, challenge students to 5. Blow the splint out after 5 in the atmosphere. (The first is nitrogen.) identify the nonmetal elements. seconds and immediately plunge the glowing splint Sulfur is the other common nonmetal in the oxygen family. If Apply Ask: Why are most nonmetals into the mouth of the test you have ever smelled the odor of a rotten egg, then you are found as part of a compound? (Sample tube. Avoid getting the already familiar with the smell of some sulfur compounds. Sul- answer: Nonmetals are very reactive.) splint wet. fur is used in the manufacture of rubber for rubber bands and learning modality: visual Observing Describe the automobile tires. Most sulfur is used to make sulfuric change in matter that (H2SO4), one of the most important chemicals used in . occurred in the test tube. What evidence indicates that oxygen was produced? 16 8 0 FIGURE 24 Oxygen

The Oxygen Family 16 Oxygen and sulfur are the most common S of the three nonmetals in Group 16. Sulfur Interpreting Tables What is the of each Group 16 element? 34 Se Selenium

52 Some of the oxygen needed Te by a frog enters through its . 84 Po

The rubber in these tires contains sulfur.

Tips Substitute wooden coffee stirrers Extend Test for the presence of carbon for splints. dioxide. Add a small amount of Skills Focus Observing L2 Expected Outcome Bubbles form in the to a test tube containing crushed shells or limestone ( Materials 3% hydrogen peroxide H2O2 after the addition of MnO2. The , , test tube, glowing splint relights and burns brightly. ). After the reaction, light a splint wooden splint, matches Sample answer: A gas was produced from and insert it into the test tube. It will be extinguished by the Time 15 minutes the reaction of a solid and a liquid. The splint relit, indicating the presence of gas. learning modality: visual oxygen. 0072_sx09_K_te_Ch03.fm Page 103 Sunday, January 13, 2008 1:38 PM

The Halogen Family Group 17 contains fluorine, chlorine, bromine, iodine, and . These elements are also known For: Links on nonmetals as the , which means “salt forming.” All but astatine Visit: www.SciLinks.org are nonmetals, and all share similar properties. A halogen atom Web Code: scn-1134 typically gains or shares one electron when it reacts with other For: Links on nonmetals Visit: www.SciLinks.org Download a worksheet that will guide students’ review elements. Web Code: scn-1134 of Internet resources on nonmetals. All of the halogens are very reactive, and the uncombined elements are dangerous to humans. is so reactive that it reacts with almost every other known substance. Even water and powdered will burn in fluorine. Chlorine gas is L3 extremely dangerous, but it is used in small amounts to kill bacteria in water supplies. Contrasting Halogens Though the halogen elements are dangerous, many of the and Noble Gases compounds that halogens form are quite useful. Compounds of carbon and fluorine make up the nonstick coating on cook- Materials art supplies, paper ware. Small amounts of fluorine compounds that are added to Time 15 minutes water supplies help prevent . Chlorine is one of the elements in ordinary table salt (the other is sodium). Another Focus Tell students that halogens are highly salt of chlorine, calcium , is used to help melt on reactive and noble gases are very unreactive. roads and walkways. Bromine reacts with to form silver Teach Challenge students to create a , which is used in photographic film. cartoon that contrasts the reactivity of halogens and noble gases. Cartoons can be a single panel or a short series, color or black and white. Encourage students to be creative. Apply Ask: What causes the difference FIGURE 25 17 The Halogens between the reactivity of halogens and 9 noble gases? (Halogens easily gain or share F The Group 17 elements are the most reactive Fluorine nonmetals. Atoms of these elements easily one electron when reacting with other form compounds by sharing or gaining one 17 elements. Noble gases do not usually gain, lose, Cl electron with atoms of other elements. or share any electrons.) learning modality: Chlorine kinesthetic

35 Br Bromine

53 I Iodine

85 At Astatine Bromine is highly reactive, and will burn skin on contact.

Fluorine-containing compounds are found in toothpaste.

Monitor Progress L2 Oral Presentation Call on students at random to give the group number and one characteristic of the oxygen family and the halogens. Answer Figure 24 Oxygen, 8; sulfur, 16; selenium, 34; tellurium, 52; and polonium, 84 0072_sx09_K_te_Ch03.fm Page 104 Sunday, January 13, 2008 1:38 PM

The Metalloids FIGURE 26 The Noble Gases Electricity makes the Group 18 Teach Key Concepts L2 elements glow brightly inside Properties of Metalloids glass tubes. Applying Concepts Why are and the other Focus Show students the location of noble gases so unreactive? metalloids in the periodic table. 18 Teach Ask: What are some properties of 2 metalloids? (They have some properties of He both metals and nonmetals. They are all solids Helium at room temperature. They are brittle, hard, 10 Ne The Noble Gases The elements in Group 18 are known as and somewhat reactive.) What is the most Neon the noble gases. They do not ordinarily form compounds useful property of metalloids? (Their 18 varying ability to conduct electricity) Ar because atoms of noble gases do not usually gain, lose, or share electrons. As a result, the noble gases are usually unreactive. Apply Explain that silicon and germanium Even so, scientists have been able to form some compounds of are metalloids used to make . 36 Ask: What is a semiconductor? (A substance Kr the heavy noble gases (Kr, Xe) in the laboratory. All the noble gases exist in Earth’s atmosphere, but only in that can conduct electricity under some 54 small amounts. Because they are so unreactive, the noble gases conditions but not under others.) What are Xe were not discovered until the late 1800s. Helium was discov- semiconductors used for? (To make computer ered by a scientist who was studying not the atmosphere but chips, , and lasers) learning 86 the sun. modality: verbal Rn Have you made use of a ? You have if you have ever purchased a floating filled with helium. Noble gases Integrating L2 are also used in glowing electric lights. These lights are com- Have students find silicon on the periodic monly called neon lights, even though they are often filled with table. Ask: Is silicon a metal, nonmetal, or argon, xenon, or other noble gases. metalloid? (Metalloid) Explain that besides being used to make computer chips, silicon Hydrogen Alone in the upper left corner of the periodic is also used to make solar cells. When table is hydrogen—the element with the simplest and smallest light strikes the junction between two atoms. Each hydrogen atom has one and one electron. semiconductors or between a metal and a Some hydrogen atoms also have neutrons. Because the chemi- semiconductor, an electron moves from cal properties of hydrogen differ very much from those of the one atom to another. Ask: What is the other elements, it really cannot be grouped into a family. charge of an atom that has gained an Although hydrogen makes up more than 90 percent of the electron? (Negative) What is the charge of atoms in the , it makes up only 1 percent of the mass of an atom that has lost an electron? (Positive) Earth’s crust, oceans, and atmosphere. Hydrogen is rarely found on Earth as a pure element. Most hydrogen is combined Explain that this transfer of charge can with oxygen in water (H O). power a small appliance or charge a 2 battery. learning modality: verbal Why were the noble gases undiscovered until the late 1800s?

1 FIGURE 27 H Importance of Hydrogen Hydrogen Water is a compound of hydrogen and oxygen. Without liquid water, life on Earth would be impossible.

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The Metalloids FIGURE 28 Monitor Progress L2 Silicon Along the border between the metals and the nonmetals are A silicon computer chip is dwarfed Answers seven elements called metalloids. These elements are shown by an ant, but the chip’s properties Figure 26 Atoms of noble gases do not in the yellow squares in the periodic table in Section 2. The as a semiconductor make it a pow- usually gain, lose, or share electrons. erful part of modern computers. metalloids have some characteristics of both metals and Because they are unreactive nonmetals. All are solids at room temperature. They are and scarce brittle, hard, and somewhat reactive. Silicon; in sand The most common metalloid is silicon (Si). Silicon com- bines with oxygen to form (SiO2). Ordinary sand, which is mostly SiO2, is the main component of glass. A compound of (B) and oxygen is added during the pro- cess of glassmaking to make heat-resistant glass. Compounds Assess of boron are also used in some cleaning materials. The most useful property of the metalloids is their Reviewing Key Concepts varying ability to conduct electricity. Whether or not a 1. a. Some nonmetals are gases at room metalloid conducts electricity can depend on temperature, temperature, while others are dull, brittle exposure to light, or the presence of small amounts of impu- 14 solids. In general, nonmetals have lower rities. For this reason, metalloids such as silicon, germanium Si densities than metals and are poor (Ge), and arsenic (As) are used to make semiconductors. Silicon conductors of heat and electricity. Except for Semiconductors are substances that can conduct electricity Group 18 elements, most nonmetals react under some conditions but not under other conditions. readily to form compounds. b. Atoms of Semiconductors are used to make computer chips, transis- nonmetals usually gain or share electrons tors, and lasers. when they react with other elements. c. At What is the most common metalloid, and where room temperature, fluorine and chlorine are is it found? gases, bromine is a liquid, iodine and astatine are solids, and all the noble gases are 4 gases. While all the halogens are very Section 4 Assessment reactive, the noble gases are usually stable and unreactive. Target Reading Skill Using Prior Knowledge Review 2. a. The metalloids are found along the your graphic organizer about nonmetals and metalloids, and revise it based on what you learned in the section. border between the metals and nonmetals Halogen Hunt Identify compounds in the periodic table. b. Sample answer: As Reviewing Key Concepts in your home that contain components of glass, cleaning materials, 1. a. Reviewing What physical and chemical properties are halogens. Look at labels on foods, computer chips, transistors, and lasers found among the nonmetals? cooking ingredients, cleaning c. Some metalloids, called semiconductors, b. Making Generalizations What happens to the atoms of materials, medicines, and cosmetics. most nonmetals when they react with other elements? The presence of a halogen is often conduct electricity under some conditions c. Comparing and Contrasting How do the physical and indicated by the words fluoride, but not under other conditions. chemical properties of the halogens compare with those chloride, bromide, and or of the noble gases? the prefixes fluoro-, chloro-, Reteach L1 2. a. Identifying Where in the periodic table are the bromo-, and iodo-. Show your Have students make a table that compares metalloids found? family these examples and describe and contrasts the properties of nonmetals b. Describing What are three uses of metalloids? properties of the halogens. and metalloids. c. Applying Concepts What property makes certain metalloids useful as “” to turn a small on and off? Assessment L2 Writing Have students write a paragraph that explains why some metalloids are used to make semiconductors.

Teaching Resources • Section Summary: Nonmetals and Metalloids Halogen Hunt L 1 Suggest students Keep Students on Track Allow make a chart to list halogens they find. students to begin testing their metal samples • Review and Reinforce: Nonmetals and Examples include toothpaste (fluorine), after you have approved their experimental Metalloids table salt (chlorine), flour (bromine), plans. Suggest that students use descriptive • Enrich: Nonmetals and Metalloids tincture of iodine (iodine), and means (e.g., well, somewhat, poorly, not at (fluorine and chlorine). all) to rate a property if they cannot measure Students might know about halogen it exactly. When students test for light fixtures. Caution students not to conductivity, they might also test nonmetals touch pesticides or halogen light bulbs. (e.g., plastics, wood) for comparison. 0072_sx09_K_te_Ch03.fm Page 106 Sunday, January 13, 2008 1:38 PM

Fx Do Floxxit Q Doadeer Alien Periodic Table L2 R Alien Periodic Table Quackzil Rhaatrap Prepare for Inquiry Key Concept Problem Materials In the periodic table, elements are classified Imagine that inhabitants of another planet send • ruler a message to Earth that contains information • periodic table from text for reference according to their properties. about 30 elements. However, the message con- Skills Objective tains different names and symbols for these ele- Procedure ments than those used on Earth. Which elements 1. Copy the blank periodic table on page 107 After this lab, students will be able to on the periodic table do these “alien” names into your notebook. • draw conclusions about the Earth names represent? of the alien elements based on atomic 2. Listed below are data on the chemical and number. Skills Focus physical properties of the 30 elements. Place the elements in their proper position in the conclusions, classifying, • classify elements based on their properties. blank periodic table. • interpret data on the properties of interpreting data, inferring elements. • infer the position of the elements on the Alien Elements periodic table. The noble gases are bombal (Bo), wobble The lightest element of all is called pfsst (Wo), jeptum (J), and logon (L). Among (Pf). The heaviest element in the group of Prep Time 5 minutes these gases, wobble has the greatest 30 elements is eldorado (El). The most Class Time 30 minutes and bombal the least. Logon chemically active nonmetal is apstrom. is lighter than jeptum. Kratt reacts with byyou to form table salt. Advance Planning The most reactive group of metals are The element doggone (D) has only Remind students to bring their textbooks xtalt (X), byyou (By), chow (Ch), and 4 in its atoms. quackzil (Q). Of these metals, chow has to lab. Floxxit (Fx) is important in the of the lowest atomic mass. Quackzil is in the life. It forms compounds made of long same as wobble. Alternative Materials chains of atoms. Rhaatrap (R) and doadeer Give students index cards to rearrange the Apstrom (A), vulcania (V), and kratt (Kt) (Do) are metals in the fourth period, but elements until they find the correct order. Or are nonmetals whose atoms typically gain rhaatrap is less reactive than doadeer. or share one electron. Vulcania is in the Magnificon (M), goldy (G), and sississ are provide extra copies of the alien same period as quackzil and wobble. periodic table. all members of Group 15. Goldy has fewer The metalloids are ernst (E), highho (Hi), electrons than magnificon. terriblum (T), and sississ (Ss). Sississ is the Teaching Resources Urrp (Up), oz (Oz), and nuutye (Nu) all metalloid with the greatest atomic mass. gain 2 electrons when they react. Nuutye • Lab Worksheet: Alien Periodic Table Ernst is the metalloid with the lowest is found as a diatomic molecule and has atomic mass. Highho and terriblum are in the same properties as a gas found in Group 14. Terriblum has more protons Earth’s atmosphere. Oz has a lower atomic Guide Inquiry than highho. Yazzer (Yz) touches the number than urrp. Invitation zigzag line, but it’s a metal, not a metalloid. The element anatom (An) has atoms with Challenge students to find specific elements a total of 49 electrons. Zapper (Z) and pie on the periodic table using clues. Ask: What (Pi) lose two electrons when they react. metal in Period 3 is slightly heavier than Zapper is used to make lightweight alloys. sodium? () Introduce the Procedure Refer students to the data for the alien elements and suggest that they work on the clues in order. Emphasize that they will need more than one clue to identify some Analyze and Conclude 4. Although there are some exceptions to the elements. 1. See the column on the next page. pattern, the atomic mass of elements usually increases as the atomic number increases. Troubleshooting the Experiment 2. Yes. Some clues identified a characteristic • Suggest that students work in pencil. belonging to only one element, such as 5. The alien periodic table does not include doggone having 4 protons, pfsst being the transition metals, , , and • Allow students to work in pairs. lightest element, and anatom having elements beyond atomic number 50. Sample Expected Outcome 49 electrons. answer: It is not likely that certain groups of See the sample data table on the next page. 3. Some clues apply to several elements, such elements would be missing in a place where as clues about a group, so you need more so many other elements are present. information to identify specific elements. 0072_sx09_K_te_Ch03.fm Page 107 Sunday, January 13, 2008 1:38 PM

Alien Periodic Table 1. Earth Alien Planet 1 18 hydrogen pfsst 1 helium bombal 2 13 14 15 16 17 chow doggone 2 boron ernsst carbon floxxit 3 nitrogen goldy oxygen nuutye 4 fluorine apstrom neon logon sodium byyou 5 magnesium zapper aluminum yazzer silicon highho Analyze and Conclude 5. Communicating Write a paragraph describ- phosphorus magnificon ing which groups of elements are not 1. Drawing Conclusions List the Earth names sulfur oz included in the alien periodic table. Explain for the 30 alien elements in order of atomic whether or not you think it is likely that an chlorine kratt number. alien planet would lack these elements. argon jeptum 2. Classifying Were you able to place some ele- quackzil ments within the periodic table with just a More to Explore calcium doadeer single clue? Explain using examples. Notice that Period 5 is incomplete on the alien rhaatrap 3. Interpreting Data Why did you need two or periodic table. Create names and symbols for germanium terriblum more clues to place other elements? Explain each of the missing elements. Then, compose a using examples. arsenic sississ series of clues that would allow another student selenium urrp 4. Inferring Why could you use clues about to identify these elements. Make your clues as atomic mass to place elements, even though precise as possible. bromine vulcania the table is now based on atomic numbers? krypton wobble xtalt Radio telescopes in New Mexico pie anatom tin eldorado Extend Inquiry More to Explore Sample answer: Democritus (De), boyle (Bo), avogadro (Av), and heisenberg (Hb) could be the names and symbols of the missing elements (though students will likely choose others). Sample clues: All the missing elements are in the fifth period. Hb and Bo are both metalloids, but Hb has a smaller mass. De is an unreactive gas. Av tends to gain one electron when it reacts. K ◆ 107