Elements and Their Place on Earth

Transcription

1 Elements and Their Place on Earth Unit: 03 Lesson: 01 Suggested Duration: 12 days Lesson Synopsis: In this unit students will be learning about elements, their name and symbol. They will also be identifying elements that comprise the earth, living things, oceans and atmosphere. This is new material for. In the previous set of TEKS, this material was covered in Grade 7. The periodic table as well as atomic structure is currently covered in Grade 8. Compounds are covered in the next lesson. TEKS: 6.5 The student knows the difference between elements and compounds. 6.5A Know that an element is a pure substance represented by chemical symbols. 6.5B Recognize that a limited number of the many known elements comprise the largest portion of solid Earth, living matter, oceans, and the atmosphere. Scientific Process TEKS: 6.1 The student for at least 40% of instructional time conducts field and laboratory investigations following safety procedures and environmentally appropriate and ethical practices. 6.1A Demonstrate safe practices during field and laboratory investigations as outlined in the Texas Safety Standards. 6.2 The student uses scientific inquiry methods during laboratory and field investigations. 6.2D Construct tables and graphs, using repeated trials and means, to organize data and identify patterns. 6.2E Analyze data to formulate reasonable explanations, communicate valid conclusions supported by the data, and predict trends. 6.4 The student knows how to use a variety of tools and methods to conduct science inquiry. 6.4A Use appropriate tools to collect, record, and analyze information, including journals/notebooks, beakers, Petri dishes, meter sticks, graduated cylinders, hot plates, test tubes, triple beam balances, microscopes, thermometers, calculators, computers, timing devices, and other equipment as needed to teach the curriculum. GETTING READY FOR INSTRUCTION Performance Indicator(s): Choose and create a visual display (e.g, mini-poster, a display board, etc.) identifying the common elements; H, He, N, O, Cl, Na, Ca, Si, P, and S by both name and chemical symbol. Include on the display a definition of an element and a graphic that indicates which elements comprise each of the following: the solid Earth, living matter, oceans, and the atmosphere. (6.2E; 6.5A, 6.5B) 1C; 5B Key Understandings and Guiding Questions: An element is a pure substance that cannot be broken down into simpler substances. What are some elements that can be found in their pure form in nature? A limited number of elements comprise the largest portion if solid Earth, living matter, oceans, and the atmosphere. Which element is found in all of the solid Earth, living things, oceans, and the atmosphere? Vocabulary of Instruction: element Materials: a penny a piece of charcoal or tincture of iodine a nickel coal a piece of lead pipe an empty aluminum tape a box with a closeable soda can a clean chicken or beef top or lid a small helium balloon bone safety goggles a small iron skillet computer 2011, TESCCC 06/15/11 page 1 of 8

2 10 interlocking plastic blocks such as Lego index cards (4 per pair) protractor (1 per student)(optional) calculator (1 per student)(optional) plain paper pliers (1 pair) 9 volt battery (1 per group) two #2 pencils (per group) piece of cardboard electrical wire scissors small beaker water electrical tape handheld pencil sharpener Appropriate materials may be substituted as needed to incorporate district resources and availability. Attachments: Handout: Element Research Cards (1 set per student) Teacher Resource: Element Research Cards KEY PowerPoint: Elements Teacher Resource: Tic-Tac-Element Teacher Resource: Tic-Tac-Element KEY Optional Handout: Break It Down (1 per student) Optional Teacher Resource: Break It Down KEY Handout: Abundance of Elements (1 per student) Optional Handout: Making a Pie Chart for Abundance of Elements ( 1 per student) Handout: Hydrolysis of Water (1 per student) Resources and References: A periodic table. Download from TEA Student Assessment Division or other source. click on Chemistry Reference Materials and go to page 4. History and description of the elements: click in left margin on Essential data and History as well as Geology and Biology links. Another site, although a little more detailed, for element information: Click on element to see details. The Element Song on School Tube: Song-1. Advance Preparation: 1. Find a variety of materials to be a physical representation of various elements. Easily obtainable items are: a penny to represent copper (Cu) a five-cent coin to represent nickel (Ni) an empty aluminum soda can (Al) a small helium balloon (He) (Use tape to attach the helium balloon to the bottom of the box and the table.) a piece of charcoal or coal for carbon (C) a clean chicken or beef bone for calcium, or a sea shell (Ca) a small iron skillet for iron (Fe) tincture of iodine (I) a piece of lead pipe or fitting to represent lead (Pb) a box with a closeable top or lid to hold all the items 2. For the Elaborate section, strip both ends of two pieces of electrical wire for each group. The wire should be long enough to attach to both the pencil ends and the 9-volt battery terminals. Snap-on caps for the batteries and wire with alligator clips may be substituted. Use the pliers to break the metal band and eraser off the pencil. If pliers are not available, have students snap off the eraser end, grasp the pencil close to the eraser, and pull up on the rest of the pencil. It is possible to purchase pencils without erasers. Do not use colored pencils as the graphite is necessary for this to work. 3. Prepare attachments as needed. Background Information: In this unit, students are asked to know and recognize some elements. Students first need to know what an element is. 2011, TESCCC 06/15/11 Page 2 of 8

3 An element is a pure substance that cannot be broken down by chemical means into other substances. A newer definition defines elements as a class of atoms that contain the same number of protons. So a pure substance contains only one type of atom. Since the structure of atoms is not studied until Grade 8, this unit addresses the first (older) definition of an element as a pure substance that cannot be broken down by chemical means into other substances. The elements and their physical and chemical properties are organized in the Periodic Table of the Elements. The lightest elements are hydrogen and helium. Hydrogen is thought to be the first element to appear after the Big Bang. The rest of the elements are naturally occurring or created in a laboratory. There are roughly 90 naturally occurring elements. The first artificially created element was Technetium in All lab created elements are radioactive with short half-lives, so if any of these atoms were present at the formation of the Earth, they are very likely to have already decayed. The most common presentation of the elements is in the periodic table. The periodic table is not studied until 8 th grade. Students will use it at this grade to identify element names and symbols. There is an internationally recognized method for nomenclature of the elements. This provides a common chemical language for scientists world-wide. Students will practice these rules as they learn to identify some common elements, including some found in the atmosphere, Earth s crust, the oceans, and in living things. GETTING READY FOR INSTRUCTION SUPPLEMENTAL PLANNING DOCUMENT Instructors are encouraged to supplement and substitute resources, materials, and activities to differentiate instruction to address the needs of learners. The Exemplar Lessons are one approach to teaching and reaching the Performance Indicators and Specificity in the Instructional Focus Document for this unit. A Microsoft Word template for this planning document is located at If a supplement is created electronically, users are encouraged to upload the document to their lesson plans as a Lesson Plan Resource in your district Curriculum Developer site for future reference. INSTRUCTIONAL PROCEDURES Instructional Procedures ENGAGE In the Box 1. Collect as many samples of elements as possible and put them in a large cardboard box. Close the box. 2. Carefully remove one item at a time from the box. Hold them up and give students a moment to identify the item. Lay each item on the table/desk. Don t explain what this is about yet. 3. Have students share some of their ideas about any possible connections these items may have. Write these on the board. 4. Tell students that these are some representations of elements. penny = copper nickel = nickel soda can = aluminum charcoal or coal = carbon chicken or beef bone = calcium iron skillet = iron tincture of iodine = iodine pipe or fitting = lead 5. Examples of pure elements found in nature: gold (Au), silver (Ag), helium (He). Notes for Teacher NOTE: 1 Day = 50 minutes Suggested Day 1 Instructional Note: Quality instruction involves opening and closing a lesson on a daily basis. During the opening, refer to the key understanding that applies to the lesson. For example: Today we are going to focus on understanding that (key understanding) by completing (activity). At the end of each period of instruction, close the lesson by asking students how (activity) helped them understand (key understanding).this could be done through an oral response or by having students write a notebook entry. Always expect students to respond in complete sentences. Materials: closeable cardboard box penny nickel aluminum soda can small helium balloon charcoal or coal piece clean chicken or beef bone small iron skillet 2011, TESCCC 06/15/11 page 3 of 8

4 tincture of iodine lead pipe or fitting tape Instructional Note: Be sure to look in the Advance Preparation section concerning the items. Use a piece of tape to hold the helium balloon in the box and on the table. EXPLORE Element Research 1. Each student should do their own research. Arrange for a computer lab access or library time for research. 2. Students should write their responses on each card. The first card is a template with an explanation of what information is expected. 3. Inform students that they should write their responses in complete sentences. Misconceptions: There is a possibility that this activity may build a misconception. It is difficult to find many everyday examples of pure elements. Some items (for example the penny, nickel, and first aid iodine) are not pure elements. Most of these samples are representations. During the lesson be sure to reinforce what an element is. Suggested Days 1 (continued), 2 and 3 Materials: reference books or computer lab Attachments: Student Handout: Element Research Cards (1 set per student) Teacher Resource: Element Research Cards KEY EXPLAIN Elements Suggested Day 4 1. Show the PowerPoint: Elements. 2. On slide 10, give students time to look at each symbol that bounces in. A new example will drop in on the mouse click. 3. Have students comment on whether the symbol is correct or not. Listen to their responses, but do not comment at this time. Instructional Note: These cards will be used again later in the lesson. Attachments: PowerPoint: Elements Teacher Resource: Tic-Tac- Element Teacher Resource: Tic-Tac- Element KEY 4. Advance to slide 11. At this point, the correct answer is obvious. Review with students why the others are incorrect. If necessary, review the rules for naming (Slide 9). Notebook: 5. Divide the students into two groups. Draw a tic-tac-toe grid on the board. Have students write the definition for Label the boxes 1 9. element in their notebook. They should also write the rules for element symbols. 6. Cut apart the questions on the Teacher Resource: Tic-Tac-Element KEY and tape them print side against the board. Instructional Note: 2011, TESCCC 06/15/11 page 4 of 8

5 7. Have one group pick a numbered box. Read the question aloud and give the students in the group 30 seconds to find the answer and write the correct symbol in the square. 8. If the answer is incorrect, the other group has a chance to write the correct answer to steal the square. If their answer is correct, they get that square and then take their regular turn. 9. The game continues until one team has completed three in a row: vertically, horizontally, or diagonally. Students do not need to know all the information on the PowerPoint. Its purpose is to give the students an idea of the scale of an element to a substance as well as the idea that elements are the smallest part of a substance. Instructional Note: You may want to develop more tic-tacelement questions for multiple attempts at winning. EXPLORE Break It Down Suggested Days 5 and 6 1. Pair up students. Each pair should receive 10 or so plastic interlocking blocks in a variety of colors. 2. Have each student construct a structure out of their blocks. The structure should have multiple colors of blocks. They are to create a key for their structure on an index card. The key identifies the type of blocks by color and/or size. 3. The paired students should then trade structures and try to figure out the pattern their partner created. Check answers on the key. 4. Have the pairs create another structure that is more complicated than the single structure they constructed previously. They are to create a key for this structure as well. 5. Each pair of students will now trade structures with another group. They will also make a key. 6. When the class pairs have traded several times, have them collect their own structure. They will then explain the pattern of blocks/colors to the class. Each pair that looked at that particular model should check the key they made and make corrections as necessary. EXPLAIN What s an Element? Suggested Day 7 1. When the activity is completed Ask: What is the smallest piece that the model would break down into? (An individual block of a specific color) What would this piece of the model represent in real life? (An element) 2. Instruct students to look at their copy of a periodic table of the elements. Ask: Materials: 10 pieces of plastic interlocking blocks, such as Lego (per pair) index cards (4 per pair) Attachments: Optional Handout: Break It Down (1 per student) Optional Handout: Break It Down KEY Instructional Notes: If blocks are not available, use the optional Handout: Break It Down instead. Students may cut out the shapes and draw a key for the shapes/ shading. For the 3 rd structure, students can combine any of the cut out shapes on the page. The purpose of this activity is to let the students understand that a substance (block structure) can be broken down into elements (individual color block). Instructional Notes: The pattern students should note is that the individual blocks join to make a larger structure. The larger structure can be broken down to the individual blocks representing elements. In this activity, the color of individual blocks indicates separate elements. Materials: highlighter (1 per student) periodic table of the elements (1 per student) 2011, TESCCC 06/15/11 page 5 of 8

6 What is the title of this chart? (Periodic Table of the Elements) What does each symbol represent? (An element that cannot be broken down) Look at your chart. What types of atoms does #26 Iron or Fe contain? (Only iron atoms) How many types of atoms in # 13 Aluminum or Al? (Only aluminum atoms) Finally, how many types of atoms in # 92 Uranium or U? (Only uranium atoms) Instructional Note: If necessary, build a model with the interlocking blocks from the previous day to show how all the atoms in an element are the same. For example connect red blocks of the same size and shape to demonstrate iron. 4. Say: There are about 90 naturally occurring elements. The rest are made in a laboratory. Although most of the elements on the chart will combine to form compounds, they cannot be broken down into a simpler substance. Elements are composed of only one type of atom. Elements are important components of the Earth s crust, the atmosphere, the oceans, and living organisms. Usually they are found combined with other elements, but some are found in their pure form. 5. Have students look at the periodic table and at the names of the elements. Connect to: Song-1. The names of the elements are spelled phonetically at the bottom of the screen. A box with the element symbol is on the screen also. Have students look at the periodic table again. This song may have to be played more than once for the students. Instructional Note: If you cannot connect to School Tube, search online for the Element Song by Tom Lehrer. There are multiple versions available. 6. Have students highlight the elements on their periodic table that are listed in the specificity: H, He, N, O, Cl, Na, Ca, Si, P, and S EXPLORE/EXPLAIN Abundance of Elements Suggested Days 8 and 9 1. Give each group a copy of Handout: Abundance of Elements. Have students read the information. Review information with the students if necessary. 2. Distribute the Handout: Making a Pie Chart for an Abundance of Elements. Demonstrate steps if necessary. 3. There is a space in each table on the Handout: Abundance of Elements for the degree conversion (or have students estimate through making a sketch). 4. Have students create pie charts (circle graphs) on blank paper for each of the 4 categories: Earth s Crust, Atmosphere, Ocean, and Living Things. 5. Please note that students could use estimation to sketch the pie charts as shown in the Instructional Notes instead of completing the calculations for constructing the pie chart with a protractor. Materials: protractor (1 per student) optional calculator (1 per student) optional pencil plain paper Attachments: Handout: Abundance of Elements (1 per student) Optional Handout: Making a Pie Chart for an Abundance of Elements (1 per student) Instructional Note: Students at this grade should be able to construct pie charts. 6.10C Probability and Statistics: The student uses statistical representations to analyze data Sketch circle graphs to display data; and 6.10D solve problems by collecting, organizing, displaying, and interpreting data. They may not have 2011, TESCCC 06/15/11 page 6 of 8

7 learned this by the time this lesson is presented, so the students may need some extra help in this area. Instructional Note: Another way for students to construct the pie chart is by estimating. As they look at the % by mass they could estimate the amount. % by Mass oxygen silicon aluminum iron calcium others ELABORATE Electrolysis of Water Suggested Day Read Advance Preparation section concerning this activity. 2. Group students and distribute the Handout: Electrolysis of Water to each group. 3. Have students read all instructions before beginning the activity. 4. After students have completed the activity: Say/Ask: The chemical symbol for water is H 2 O. What elements make up water? (Hydrogen and oxygen) Electrolysis is the breaking apart of water using electricity. When water is broken apart by an electric current, the hydrogen will be attracted to the pencil attached to the negative side of the battery and the oxygen will be attracted will be attracted to the pencil attached to the positive side of the battery. What do the bubbles represent? (The gases) Materials: per group 9 volt battery two #2 pencils pliers handheld pencil sharpener piece of cardboard electrical wire electrical tape small beaker warm water Attachments: Handout: Hydrolysis of Water (1 per student) EVALUATE Performance Indicator Suggested Days 11 and 12 Performance Indicator Choose and create a visual display (e.g., mini-poster, a display board etc.) identifying the common elements; H, He, N, O, Cl, Na, Ca, Si, P, and S by both name and chemical symbol. Include on the display a definition of an element and a graphic that indicates which elements comprise each of the following; the solid Earth, living matter, oceans, and the atmosphere. (6.2E; 6.5A, 6.5B) 1. Instruct the students to create a visual display of their choice. It may be a mini-poster, a display board, or a 3-dimentional display such as a diorama. 2. Instruct the students to include: H, He, N, O, Cl, Na, Ca, Si, P, and S. Materials: materials needed for visual displays 2011, TESCCC 06/15/11 page 7 of 8

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9 Element Research Cards Template Elements Symbol Name H Hydrogen Why named: Why named: What language did the element name come from? What does the name mean? Person(s) who discovered the element. State of matter: Is the element a liquid, solid, or gas? Briefly describe the physical characteristics of the element such as odor, color, shape, shine, etc. Atmosphere Oceans Earth s crust 2011, TESCCC 06/15/11 page 1 of 6

10 Element Research Cards He Helium N Nitrogen Why named: Why named: 2011, TESCCC 06/15/11 page 2 of 6

11 Element Research Cards O Oxygen C Carbon Why named: Why named: 2011, TESCCC 06/15/11 page 3 of 6

12 Element Research Cards Cl Chlorine Na Sodium Why named: Why named: 2011, TESCCC 06/15/11 page 4 of 6

13 Element Research Cards (p.p. 5 of 6) Ca Calcium Si Silicon Why named: Why named: 2011, TESCCC 06/15/11 page 5 of 6

14 Element Research Cards P Phosphorus S Sulfur Why named: Why named: 2011, TESCCC 06/15/11 page 6 of 6

15 Element Research Cards KEY Template Elements Symbol Name H Hydrogen What the element name means: What language did the element name come from? What does the name mean? What the element name means: From the Greek words "hydro" and "genes" meaning "water" and "generator" Person(s) who discovered the element Hydrogen was discovered by Henry Cavendish at 1766 in London, England. State of matter: Is the element a liquid, solid, or gas? Gas Briefly describe the physical characteristics of the element such as odor, color, shape, shine, etc. Colorless Lightest element Atmosphere Earth s crust Oceans Living things Atmosphere 2011, TESCCC 06/15/11 page 1 of 6

16 Element Research Cards KEY He Helium N Nitrogen What the element name means: From the Greek word "helios" meaning "sun" What the element name means: From the Greek words "nitron genes" meaning "nitre" and "forming" and the Latin word "nitrum" Helium was discovered by Sir William Ramsay and independently by N. A. Langley and P. T. Cleve at 1895 in London, England and Uppsala, Sweden. Gas Nitrogen was discovered by Daniel Rutherford at 1772 in Scotland. Gas Colorless Odorless Light Colorless Earth s crust Atmosphere 2011, TESCCC 06/15/11 page 2 of 6

17 Element Research Cards KEY O Oxygen C Carbon What the element name means: From the Greek words "oxy genes" meaning "acid" (sharp) and "forming" (acid former) Oxygen was discovered by Joseph Priestley, Carl Scheele at 1774 in England, Sweden. Gas What the element name means: From the Latin word "carbo" meaning "charcoal" Known since ancient times Solid Odorless Colorless Tasteless Black Atmosphere Earth s crust 2011, TESCCC 06/15/11 page 3 of 6

18 Element Research Cards KEY Cl Chlorine Na Sodium What the element name means: From the Greek word "chloros" meaning "pale green" What the element name means: From the Latin word "natrium" meaning soda Chlorine was discovered by Carl William Scheele at 1774 in Sweden. Gas Sodium was discovered by Sir Humphrey Davy at 1807 in England. Solid Yellowish- green Bad odor-fatal if breathed Silvery-white Metallic Atmosphere Earth s crust 2011, TESCCC 06/15/11 page 4 of 6

19 Element Research Cards KEY Ca Calcium Si Silicon What the element name means: From the Latin word "calx" meaning "lime" What the element name means: From the Latin word "silicis" meaning "flint" Calcium was discovered by Sir Humphrey Davy at 1808 in England. Silicon was discovered by Jöns Jacob Berzelius at 1824 in Sweden. Solid Solid Silvery-white Dark grey-bluish Earth s crust Earth s crust 2011, TESCCC 06/15/11 page 5 of 6

20 Element Research Cards KEY P Phosphorus S Sulfur What the element name means: From the Greek word "phosphoros" meaning "bringer of light" Phosphorus was discovered by Hennig Brand at 1669 in Germany. What the element name means: From the Sanskrit word "sulvere" meaning "sulphur"; also from the Latin word "sulphurium" meaning "sulphur" Sulfur has been known since ancient times. Solid Solid Exists in several forms including white, yellow, red, and black or violet. The white variety will not dissolve in water and will spontaneously burst into flames when exposed to air. Pale yellow Odorless Brittle Living things Earth s crust 2011, TESCCC 06/15/11 page 6 of 6

21 Tic-Tac-Element What element is needed for healthy bones and teeth? Which element makes up most of the Earth s crust? Which element is found in coal and diamonds? Which element is the Sun burning for fuel? What is one of two elements that start with an A that are used for jewelry? What element is put in balloons so they float? Which element do we have to breathe to stay alive? Which gas is fatal if breathed? What is the most abundant gas in the atmosphere that neither helps nor harms us to breathe? 2011, TESCCC 06/15/11 page 1 of 1

22 Tic-Tac-Element KEY What element is needed for healthy bones and teeth? Ca Which element makes up most of the Earth s crust? Si Which element is found in coal and diamonds? C Which element is the Sun burning for fuel? H What is one of two elements that start with an A that are used for jewelry? Au or Ag What element is put in balloons so they float? He Which element do we have to breathe to stay alive? O Which gas is fatal if breathed? Cl What is the most abundant gas in the atmosphere that neither helps nor hurts us to breathe? N 2011, TESCCC 06/15/11 page 1 of 1

23 Breaking It Down 2011, TESCCC 06/15/11 page 1 of 1

24 Breaking It Down KEY 2011, TESCCC 06/15/11 page 1 of 1

25 Making a Pie Chart for Element Abundance (Optional Activity) 1. Complete the data table showing the element name, the percentage by mass, and the conversion to degrees. 2. Convert each percentage into degrees by multiplying it by 3.6, which is the number you arrive at when you divide 360 (degrees in a circle) by 100 (total amount in percentage). 3. Add the total of all items to make certain that the total is equal to 360. If not, recalculate the degrees for each item. 4. Use your protractor to draw a circle to represent the whole. Make it large enough so that those viewing your circle graph can read it easily. 5. Divide the circle into segments using degrees you calculated. Mark the center of circle with a dot. Draw a radius from the center to the edge. Label this line as Line up the 0 on the protractor with the 0 radius line. Measure and mark the number of degrees needed. Draw a line from the center to the new degree mark. Label this segment with the element name and percent. 7. Continue through your calculated degrees using the previously made line as the new 0 beginning and measuring out the necessary number of degrees for each category. 8. Label each section. Color-code the sections to show the difference. 0 Radius line 2011, TESCCC 06/15/11 page 1 of 1

26 Abundance of Elements The outermost layer of the Earth is called the crust. Most of it is made from only five elements. It is rare for elements to occur alone although some like gold and silver do. Proportions by mass (rounded) for the Earth s crust: ELEMENT % BY MASS Oxygen 47% Silicon 28% Aluminum 8% Iron 5% Calcium 3% Others 9% DEGREE The atmosphere surrounding the Earth is called the atmosphere. It is held in place by gravity and protects life by absorbing ultraviolet radiation from the Sun and reducing temperature extremes between day and night. The oxygen in the atmosphere is necessary for most life on Earth. Proportions by mass (rounded) for the Earth s atmosphere: ELEMENT % BY MASS Oxygen 21% Nitrogen 78% Others 1% DEGREE Ocean water is about 97% water, and the rest is elements and gases. There have been around 84 elements identified in sea water. Proportions by mass (rounded) for the Earth s oceans: ELEMENT % BY MASS Oxygen 85% Hydrogen 10% Chlorine 2% Sodium 1% Others 2% DEGREE By mass, human cells consist of 65-95% water. In the human body, 99% of the mass is made up of six elements. The very common element in the earth s crust, silicon, is absent in the human body as well as in most life on Earth. Proportions by mass (rounded) found in humans as a representative of life on Earth. ELEMENT % BY MASS Oxygen 65% Carbon 18% Hydrogen 10% Nitrogen 3% Calcium 2% Phosphorus 1 % Others 1% DEGREE 2011, TESCCC 06/15/11 page 1 of 1

27 Hydrolysis of Water Materials: 9 volt battery electrical wire warm water two #2 pencils small beaker electrical tape piece of cardboard pliers handheld pencil sharpener safety goggles 1. Use the pliers to remove the erasers and metal ends from pencils, and sharpen both ends of each pencil. 2. Cut a piece of cardboard to fit over the beaker top. 3. Make two small holes in the cardboard about one inch apart. Push one the ends through the holes using one pencil per hole. Hold pencils in place with tape if necessary. 4. Strip insulation from the ends of the electrical wire with scissors. 5. Attach one end of a piece of electrical wire to the positive side of a 9-v battery. Attach the opposite end to the graphite tip of one pencil. Ensure the wire makes contact with the graphite by using electrical tape to secure the wire to the pencil point. 6. Attach one end of the other electrical wire to the negative side of the battery. Attach its opposite end to the graphite tip of the other pencil with electrical tape. 7. Fill small beakers about two-thirds full with warm water. 8. Suspend the wireless pencil ends in the water resting the cardboard on the top of the glass. Do not allow the pencils to touch the bottom of the glass. 9. Wait for about a minute. Look closely to observe the bubbles that form around the pencil tips in the water. Step # 3 Steps # 5 & 6 Steps # , TESCCC 06/15/11 page 1 of 1

28 Breaking It Down KEY 2011, TESCCC 06/15/11 page 1 of 1