TEACHERS GUIDELINES BUCKYBALLS

Transcription

1 NTSE - Nano Technology Science Education Project No: LLP TR-KA3-KA3MP TEACHERS GUIDELINES BUCKYBALLS Contents 1. Foreword for Teachers 2. Introduction 3. Learning Process 4. Conclusion 5. Evaluation The lesson plan is created to help high school science teachers an introduction to Buckyballs in a classroom setting and make use of the information provided on the web site ( ). Target Group Student groups aged Duration School Subject Areas 90 minutes Physics - Chemistry - Biology Lesson Goal The Buckyball lesson provides the opportunity to explore and understand the crystal structures of allotropes of carbon. Students will find out the differences and similarities of allotropes of carbon. The lesson introduces the Buckyball and Carbon Nanotubes and their application areas. Lesson Objectives To learn about allotropes of carbon. To learn about buckyball structure. To learn about application areas of buckyballs and carbon nanotubes. To learn about different covalent bond structures of carbon. To learn about crystal structure of allotropes of carbon. Required Student Pre-knowledge To know the following terms that exist in the reading text: Types of atoms (isotopes, isobar, isotone, isoelectronic, allotrope) Lewis structure of molecules (molecular geometry) Types of bonding Anticipated Learner Outcomes To understand types of carbon allotropes. To link carbon nanotube and buckyball with nanotechnology. 1

2 To acquire knowledge about the variation of physical properties of a certain chemical substance according to its different molecular structure types. Material & Resources Reading text for the students Experiment video Activity materials Student Assessment or Evaluation Student worksheet Student quiz FOREWORD FOR TEACHERS Short Description of the Activity and Short Theoretical Background The carbon atom is one of the most important building blocks in the field of nanotechnology. It earned this distinction over atoms of any other element on the periodic table because of its unique bonding ability. When carbon atoms bond with different types of atoms, they form molecules that display the properties of the atoms with which they are bonded. In this activity it is aimed to let the students acquire the knowledge of Buckyball and Carbon nanotubes crystal structures, their properties and application areas. INTRODUCTION The teacher tries to raise students awareness by asking the questions below. (Leading the students to give the probable feedback similar to those answers below) Question 1: Which two of the following have a great similarity in common in atomic structure; salt, diamond, coal, gold, and silver? Diamond and coal. Question 2: How can such different looking materials have this much similarity? Because they are allotropes of the same element: carbon. Allotropes are different structural modifications of an element. They have different physical properties, but the same chemical properties. Question 3: Do you know about other famous allotropes in the nature? Oxygen gas - Ozone White phosphorus - Red phosphorus C (diamond) - C (diamond) - C (graphite) and Fullerenes. Question 4: You probably know about bowling ball, disco ball, and tennis ball. Likewise, have you heard about buckyball? What is a buckyball? 2

3 Buckyball is a spherical fullerene molecule with the formula C. It has a cage-like ring structure which resembles a classical soccer ball, with 20 hexagons and 12 pentagons, with a carbon atom at each vertex of each polygon and a bond along each polygon edge. Question 5: Other than buckyball ( C Carbon nanotubes, carbon megatubes. C, C and etc. ), what kind of Fullerene molecules can you name? LEARNING PROCESS Before the Lecture Assignment: Providing the students the text on BUCKYBALLS and asking them to read it. Before Class Preparations: Designing the room to watch the experiment videos. Preparing the materials needed in activities explained below. In the Lecture Step -1: Watching students the the animation on the website; The Scale of the Universe 2 Step-2: Asking the following question about the text. Question 6: To what scale is C60 molecules (buckyballs) equivalent? (Answer according to the previous animation named The Scale of the Universe 2 ) Emphasize the size of nanometres. Alpha Helix, Cs atom, X-ray wavelength and buckyball are nearly at the same size. Step-3: Starting the Activity-1 described in Students Guidelines. Step -4: Asking the following questions about the activity. Question 7: Define how many times the model Buckyball you have built is bigger than the actual Buckyball molecule by supposing that the actual Buckyball and the model Buckyball you ve built are in spherical shape? By measuring the radius of the model with the help of a ruler, try to calculate how many Buckyballs in nanoscale could form that length. Note on the board that 1 m is 10 9 nm. 3

4 y Indicate that the Buckyball model is 3- dimensional. To help the students realize these dimension first show Fig.1 to the students, then give them three sticks and ask them to place the sticks on their models. z x Figure 1: system. (1) C on the coordinate Question 8: Crumple up another carton paper to be the same size as Buckyball you have built. Press both of them and compare the differences (figure 2). What can you say for this comparison? Which of them is stronger? Why? Bucykball is more durable than crumpled paper. Spherical structures distribute the forces applied in equal pieces on their surfaces. Figure 2: Buckyball and Crumple up another carton paper. Step -5: Starting the Activity-2 described in Students Guidelines. Step-6: Asking the following question about the text. Question 9: Build a cubic prism nearly at the same volume as your Buckyball with another carton paper. Press them both with the same force and discuss the results. Buckyball is more durable than cubic prism. Question 10: What kind of bonding is there in between the carbon atoms of fullerene? Covalent bonding. Question 11: Carbon nanotubes are the strongest and lightweight material yet discovered. What can be the application areas of carbon nanotubes? Buildings, batteries, solar panels, space vehicles, and so on Question 12; We know that fullerenes show superconducting properties. Which research areas are related to super-conductivity? Search for the application areas of superconductor. Magnetic-levitation (2), 4

5 Super conducting magnets especially for transport such as trains (3), Biomagnetism, Electric generators made with superconducting wire, Energy storage to enhance power stability, "Petaflop" computers. CONCLUSION Question 13: Why do you think Fullerenes dissolve in toluene or CS2, but not in water? We know the principle Substances can be dissolved in solvents with similar properties. Water is a polar solvent, but fullerenes are nonpolar substances. That s why they can only be dissolved in nonpolar solvents. Figure 3: C solution (4) Assignment What is the significance of fullerenes in industry, health and science? Buckyballs have evidence of superconductivity. How do you think that the superconductivity of Buckyballs can be increased? By doping metal ions. As caesium forms the largest alkali ion, caesiumdoped buckyball have different physical properties. Caesium-doped buckyball is an important material. Recently, superconductivity K at has been reported in bulk Cs C, but only under applied pressure. Figure-4:Cs3C60 Figure 4: Cs crystal structure. structure.(5) C EVALUATION Quiz Assement Grid A. Write (T) True or (F) False for the statements below. (5minutes) ( ) 1- Graphite is a conductor and can be used as the material in the electrodes of an electric arc lamp. ( ) 2- Allotropes have different physical properties and the same chemical properties. 5

6 ( ) 3- The atoms forming allotropes have the same kind of bonding in between, but in different manners. ( ) 4- Diamond is a hollow cluster of 60 carbon atoms shaped like a soccer ball. B. Fill in the blanks with an appropriate expression.(5 minutes) 1- Buckyball is a molecule with the formula C are different structural modifications of an element is the hardest natural mineral. KEY Write (T) True or (F) False 1- T 2- T 3- F Fill in the blanks 1- Spherical 2- Allotropes 3- Diamond REFERENCES (1) (2) ( ) (3) (4) (5) 6