Chemical Bonds in the Nanoworld

 

Mary C. Hobbs, Educator, MathScience Innovation Center

 

Developed with funding from the MathScience Innovation Center

 

Major

Understanding

Students will understand the relationship between number and types of bonds and the resulting properties and shapes of molecules. As an extension of this concept, they will see the unusual properties of nanoscale aggregates created by forces that exist at the atomic scale.

 

Grade/Subject

Chemistry Grades 10-12 and Physical Science Grade 8

 

Objectives

Students should understand that structural formulas also show the arrangement of atoms and bonds.

 

Students should predict, draw, and name molecular shapes (linear, trigonal, and tetrahedral).

 

Students should comprehend that all matter is composed of atoms that are in constant motion and interact with each other to form molecules. The arrangement of these atoms or nanoscale particles into aggregates gives each material its properties.

 

Students will be able to describe that the use of models are needed to understand, visualize, predict, and interpret data about nanoscale objects that are too small to see.

 

Students will be able to describe the range of electrical forces which exist on the nanoscale, with varying strengths that tend to dominate the interaction between objects.

 

Time

Anticipatory Set—Science Toys and Models

5 min

 

Introduction: Part 1 Big Ideas of Nanoscience

5 min

 

Introduction: Part 2 Chemical Bonds

5 min

 

Activity: Magic Sand Investigation

15 min

 

Discussion: How to Use Model Kits

10 min

 

Activity: Building Chemical Models and Determining Shapes

20 min

 

Activity: Using the Fold-A-Matic to Study Molecules

10 min

 

Discussion: New Carbon Materials and Nanoproperties

10 min

 

Wrap Up: Challenge to Find Your Role in Nanoscience

View Video of Dr. Kroto’s Description of his Discovery

10 min

 

 

Materials

For the class:

·         PowerPoint on Chemical Bonds in the Nanoworld

·         Water

 

For each group of students:

·         1 set of six carbon model kits

·         1 Organic Fold-A-Matic for each student or group www.flinnsci.com

·         1 set of three samples of three kinds of sand

·         Filter paper, funnel, beakers, spoons, plastic cup

·         Worksheet: Where is the Magic? Data Sheet

·         Instruction sheets for Magic Sand and Organic Fold-A-Matics:

Ø      Where is the Magic? (sand instructions)

Ø      Using an Organic Fold-A-Matic

 

State and National

Correlations

Virginia Standards of Learning: CH.3(a), (b), (c), (d); 2010 Chemistry (CH.3)

 

National Science Education Standards: NS.9-12.2

 

21st Century Curriculum

Nanoscience: Structure of Matter, Forces, Models & Simulations

 

Instructional

Strategies

1.      Anticipatory Set

1.1.       Show students models of graphite and buckyball.

1.2.       Ask them what they can observe about these models—what is similar and what is different; ask if they know what they are and what they represent; what atoms are present, where are they, where are the bonds, what bonds do?

 

2.      Introduction: Part 1: The Big Ideas of Nanoscience

2.1.       Begin PowerPoint Chemical Bonds in the Nanoworld: Unique Properties & Behaviors—nanocoatings—we will see more about these later on.

2.2.       Size & Scale—one calcium phosphate aggregate is measured in nanometers.

2.3.       Tools & Techniques—the AFM is one of the most useful instruments.

2.4.       Societal Implications—fear of nanoscience often comes from lack of knowledge—we will study carbon bonds to understand nanoscience.

2.5.       Nanotech Applications—carbon nanotubes may be used by NASA.

3.      Introduction: Part 2: Chemical Bonds

3.1.       ACD/ChemSketch is used to draw molecules of covalently bonded molecules.

3.2.       Famous scientists studied bonds.

3.3.       Covalent Bonds—atoms sharing electrons.

3.4.       Van der Waals forces—“weak“ attraction between molecules of uneven electron distribution with partial positive and partial negative charge.

3.5.       Van der Waals forces are SIGNIFICANT at the atomic scale.

4.      Activity: Magic Sand Investigation

4.1.       Hand out sample trays to students either sand sample #1 or #2 or #3.

4.2.       Each group fills out the data chart Where is the Magic? Data Sheet for their one sand sample.

4.3.       Use the data chart to share information from all groups so that all students have a complete data chart.

4.4.       Discussion of magic sand’s properties and applications.

5.      Discussion: How to Use Model Kits

5.1.       Introduction—bonds determine shape and strength of molecules.

5.2.       Show slides in PowerPoint of types of molecule models, tell their importance, and the models that will be used today.

6.      Activity: Building Chemical Models and Determining Shapes

6.1.       Hand out sets of model kits with 6 models in each.

6.2.       Students build each model, draw each model, complete the formula chart, Building Models.

6.3.       Students build on this knowledge to complete the second organic chart.

6.4.       Take the quick quiz to match the molecules.

6.5.       Relate molecules to magic sand—methane is a COMPLETED methyl.

6.6.       Hand out the Fold-A-Matic Instructions, Fold-A-Matic Data Sheets, and Fold-A-Matics.

6.7.       Use the Fold-A-Matic to make more molecules.

7.      Discussion: New Carbon Materials and Nanoproperties

7.1.       Recognition of the usual bonding of carbon=4 bonds sp3 hybridized orbitals.

7.2.       Review of shapes and their bonds.

7.3.       What are buckyballs or fullerenes and how are they used?

7.4.       What is different about their bonds==van der Waals forces?

7.5.       How are the fullerenes made?

7.6.       Remember their history.

7.7.       More practical uses for fullerenes.

7.8.       Current research.

7.9.       It’s all in the electrons==armchair CNTs (Carbon Nanotubes) are conductive.

7.10.   Van der Waals forces make CNTs very strong.

8.      Wrap up Challenge: Find Your Role in Nanoscience

8.1.       Some industries are already researching nanoproducts.

8.2.       Some industries are already using nanoproducts.

8.3.       Remember the work of the two men who led us to understand carbon bonds.

9.      Reflection: Where is the Science of Carbon Bonds Going?

9.1.       View video of Dr. Kroto from the http://www.geoset.info/ Web site

 

Practice

Complete the back of the organic hydrocarbon worksheet and calculate the formulas of alkene and alkyne molecules.

 

Materials needed: Finding the Patterns worksheet

 

Closure

Find Your Role in Nanoscience

·         What new challenges face scientists?

·         What jobs will relate to solving these challenges?

 

Extensions

Make your own buckyball model.

Materials needed: Instruction sheet and pattern from ChemMatters article on Buckyballs.

 

Assessment

Sample items are provided for use in checking students’ understanding.

·         Paper Pencil Test: Chemical Bonds Assessment

·         Chemical Bonds in the Nanoworld Assessment Answer Key

·         Product and Rubric: Creating and Naming New Organic Molecules

·         Chemical Bond Project

·         Chemical Bond Project Rubric

The following table shows how the assessment items are related to specific objectives.

 

Objective

Paper-Pencil

Test

Product/

Performance

Understand that structural formulas also show the arrangement of atoms and bonds.

1,2,3

Project and Assessment

Predict, draw and name molecular shapes (linear, trigonal, and tetrahedral).

5,6,11

Project and Assessment

Students should comprehend that all matter is composed of atoms that are in constant motion and interact with each other to form molecules and that the arrangement of these atoms or nanoscale particles into aggregates gives each material its properties.

4,7,8,9,

10,13

Assessment

Students will be able to describe that the use of models are needed to understand, visualize, predict, and interpret data about nanoscale objects that are too small to see.

12,13

Project and Assessment

Students should be able to describe the range of electrical forces which exist on the nanoscale, with varying strengths that tend to dominate the interaction between objects.

14,15

Assessment

 

Teaching Tips

Some tips about the materials used in this lesson:

1.      Where do we get the supplies:
Magic Sand comes from Educational Innovations

http://teachersource.com

      Craft Sand comes from a local craft store

      Beach Sand comes from a home supply store

      Model Kits are created from the student kits from Darling Models

      www.darlingmodels.com

 

      Organic Fold-A-Matics are ordered from Flinn Scientific           

      http://www.flinnsci.com/

 

2.      What are the answers to the Paper/Pencil test?

1. D      2. D     3. C     4. B      5. C     6. A     7. D     8. C

9. D      10. B   11. A   12. A    13. C   14. D   15. A

 

References

MathScience Innovation Center
Information on educational programs available to students, teachers, and school divisions and procedures for registering for programs.
http://msinnovation.info

 

MathinScience.info: On-Line Educational Programs
Learn through on-line virtual classrooms, Web-based lessons, and online courses. Access proven lesson plans and instructional modules.
http://mathinscience.info

 

Geoset Web site

Students and teachers can view videos of famous scientists explaining their own discoveries. There are also fun videos of graduate students answering student questions about science with experimental results.

www.geoset.info

 

For more activities see the related document that offers ideas for in-class and independent activities related to nanoscience.

Bond Websites.doc

 

UVA’s Web site to see AFM in detail and nanocarbon video.

http://virlab.virginia.edu/VL/contents.htm

 

Download a simple AFM applet.

http://www.nanoscience.com/education/software.html