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LSS ACE Project Is Glass a Solid or Liquid?

LSS ACE Project Is Glass a Solid or Liquid?. Presented by: Lee Liak Ghee 2i3 (10). Introduction. Introduction. What is solid? Fixed shape & volume Molecules closely packed, vibrates about fixed positions Strong intermolecular bonds What is liquid? Indefinite shape & fixed volume

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LSS ACE Project Is Glass a Solid or Liquid?

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  1. LSS ACE ProjectIs Glass a Solid or Liquid? Presented by: Lee Liak Ghee 2i3 (10)

  2. Introduction

  3. Introduction • What is solid? • Fixed shape & volume • Molecules closely packed, vibrates about fixed positions • Strong intermolecular bonds • What is liquid? • Indefinite shape & fixed volume • Molecules in clusters, slide over one another • Weak intermolecular bonds

  4. Solids • Crystalline molecular structure • Molecules vibrate about fixed positions • Heat increases vibrations • Melting point • molecules start to flow • lose crystalline structure • Distinct phase transition • melting/freezing involves heat of fusion

  5. Liquids • Viscosity: resistance to flow • e.g. water 0.01 poise; thick oil 1.0 poise • Cooling a liquid - increases viscosity • Below melting point • molecules form crystals and solidify • Super-cooled liquid - remains liquid below freezing point • Depends on nucleation sites

  6. What is Non-newtonian?

  7. What is Glass made of?

  8. What is Glass Made of? • 2 types: • Natural Glass and Man-made Glass • Natural Glass • Formed when rocks melt • Lightning • Volcanic eruptions • Amorphous structure • High Silicon Dioxide(SiO2) capacity • Examples: Obsidian and Tektite

  9. Natural Glasses • Obsidian • Tektite

  10. Man-made Glass • Made of sand, soda ash & limestone • Heated to a high temperature • Cooled • Transparent, non-crystalline material formed

  11. Who and How was Glass Discovered?

  12. Who and How was Glass Discovered? • Natural glass • In use since the stone age • Man-made glass • In use as far back as 5000 years ago • Discovered by the ancient Egyptians

  13. Molecular Structure of Glass

  14. Molecular Structure of Glass • Amorphous structure • Long chain of atoms • No crystalline structure

  15. Characteristics of Glass

  16. Characteristics of Glass • Amorphous solid • Brittle • Transparent

  17. Glass: Solid or Liquid?

  18. How Glass is Formed • Supercooled liquid cools further • Molecules remain disordered • Develops rigidity • Becomes amorphous solid • e.g. amorphous ice forms at -137 °C • Glass is formed in this manner

  19. Glass is Liquid? • Old glass panes thicker at the bottom than the top • Some glass panes sagged • Some have rippled surfaces • Glass is a liquid with very high viscosity? • Solid has viscosity ≥ 1013 poiseLiquid has viscosity < 1013 poise

  20. Proof: Glass does not flow • Excellent images of telescope lenses • Stone age arrow heads remain sharp • Excellent condition of 1st century A.D. Roman glassware Stone Age Arrow Head 1st Century A.D. Roman Glassware

  21. Conclusion

  22. Conclusion • From our viewpoint  glass is solid • Scientific arguments are less conclusive

  23. Non-newtonian Pool

  24. Acknowledgement • http://www.wisegeek.com/what-is-glass.htm • http://www.glassonline.com/infoserv/history.html • http://www.coleparmer.com/techinfo/techinfo.asp?htmlfile=Properties_Glass.htm&ID=608 • http://math.ucr.edu/home/baez/physics/General/Glass/glass.html • http://abyss.uoregon.edu/~js/ast123/lectures/lec04.html • http://www.google.com/imgres?imgurl=http://www.b14643.de/Tektites/Vredefort_1.jpg&imgrefurl=http://www.b14643.de/Tektites/index.htm&h=264&w=365&sz=16&tbnid=YXuCMoxBWuI06M:&tbnh=88&tbnw=121&prev=/images%3Fq%3Dnatural%2Bglasses&usg=__VrGWsbDtjM_owIIzwTP2wGCF3sU=&ei=wzXZS_PjOcOyrAeXtJTTDw&sa=X&oi=image_result&resnum=2&ct=image&ved=0CAgQ9QEwAQ

  25. Acknowledgement • http://wiki.answers.com/Q/Who_discovered_glass • http://wiki.answers.com/Q/What_is_the_structure_of_glass • http://en.wikipedia.org/wiki/Glass • http://image.absoluteastronomy.com/images/encyclopediaimages/a/ar/arrowhead.jpg • http://www.youtube.com/watch?v=f2XQ97XHjVw&feature=related • http://www.youtube.com/watch?v=gi-ITHJuTpQ&feature=related • http://internationaltradecommodities.suite101.com/article.cfm/how_is_glass_made

  26. The End Thank You

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