LSS ACE Project Is Glass a Solid or Liquid?
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LSS ACE Project Is Glass a Solid or Liquid? Presented by: Lee Liak Ghee 2i3 (10)
description
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 - PowerPoint PPT Presentation
Transcript of LSS ACE Project Is Glass a Solid or Liquid?
LSS ACE ProjectIs Glass a Solid or Liquid?
Presented by:
Lee Liak Ghee 2i3 (10)
Introduction
IntroductionWhat 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
SolidsCrystalline molecular structure
Molecules vibrate about fixed positions
Heat increases vibrations
Melting pointmolecules start to flow
lose crystalline structure
Distinct phase transitionmelting/freezing involves heat of fusion
LiquidsViscosity: resistance to flow
e.g. water 0.01 poise; thick oil 1.0 poise
Cooling a liquid - increases viscosity
Below melting pointmolecules form crystals and solidify
Super-cooled liquid - remains liquid below freezing point
Depends on nucleation sites
What is Non-newtonian?
What is Glass made of?
What is Glass Made of?2 types:
Natural Glass and Man-made Glass
Natural GlassFormed when rocks melt
Lightning
Volcanic eruptions
Amorphous structure
High Silicon Dioxide(SiO2) capacity
Examples: Obsidian and Tektite
Natural GlassesObsidian Tektite
Man-made GlassMade of sand, soda ash & limestone
Heated to a high temperature
Cooled
Transparent, non-crystalline material formed
Who and How was Glass Discovered?
Who and How was Glass Discovered?
Natural glassIn use since the stone age
Man-made glassIn use as far back as 5000 years ago
Discovered by the ancient Egyptians
Molecular Structure of Glass
Molecular Structure of GlassAmorphous structure
Long chain of atoms
No crystalline structure
Characteristics of Glass
Characteristics of GlassAmorphous solid
Brittle
Transparent
Glass: Solid or Liquid?
How Glass is FormedSupercooled 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
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
Proof: Glass does not flowExcellent 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
Conclusion
ConclusionFrom our viewpoint glass is solid
Scientific arguments are less conclusive
Non-newtonian Pool
Acknowledgementhttp://www.wisegeek.com/what-is-glass.htmhttp://www.glassonline.com/infoserv/history.htmlhttp://www.coleparmer.com/techinfo/techinfo.asp?htmlfile=Properties_Glass.htm&ID=608http://math.ucr.edu/home/baez/physics/General/Glass/glass.htmlhttp://abyss.uoregon.edu/~js/ast123/lectures/lec04.htmlhttp://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
Acknowledgementhttp://wiki.answers.com/Q/Who_discovered_glasshttp://wiki.answers.com/Q/What_is_the_structure_of_glasshttp://en.wikipedia.org/wiki/Glasshttp://image.absoluteastronomy.com/images/encyclopediaimages/a/ar/arrowhead.jpghttp://www.youtube.com/watch?v=f2XQ97XHjVw&feature=relatedhttp://www.youtube.com/watch?v=gi-ITHJuTpQ&feature=relatedhttp://internationaltradecommodities.suite101.com/article.cfm/how_is_glass_made
The EndThank You
