Why don't most acids burn through glass?
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Glass is made of sand. Sand has the chemical formula of SiO2 (silicon dioxide). Although it seems to "look" like a base and some may expect it to react with an acid, this appearance is not true.\n\nSilicon is a non-metal and silicon dioxide is a macromolecule with a giant structure like that of diamond (tetrahedral). I.e. one silicon atom is attached to 4 oxygen atoms and the total ratio of Si to O is 1:2 (thus the chemical formula).\n\nDue to this, the macromolecule doesn't react with acids and so it is safe to carry acids of very high concentrations.
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interior of cup expands faster than exterior of cup due to poor thermal conductivity of the cup material.\n\nglasses that are thin enough will not suffer this problem because heat can conduct thru thin materials easily so that thermal expansion is more or less equal on the interior and exterior.\n\nyou can also force one of your glasses to break by cooling the glass with ice water, dumping the ice water away and then dousing the glass with boiling water. try not to hurt yourself.\n\nbicycle tire ruptures due to a simpler explanation. the tire cannot withstand increased pressures that occur when a gas is heated in a closed system. (gay-lussac law)
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Silicon is typically the main ingredient in glass however different elements and compounds are added to color glass or make it stronger.  Windows with high R values are filled with an inert gas such as Argon in beween two plates to increase energy efficiency.  The case protecting the Declaration of Independence and other important US documents are also filled with argon.
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Acetate will burn really well if is divided up so that air can get to it.  It is flammable enough that movie film, when stored in large quantities,like in a movie studio vault, is considered a special fire hazard.
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I believe it has to do with oxidation.  The minute you slice an apple open you are exposing it to oxygen, which breaks down the molecules of the apple. I also believe it has something to do with the sugar content.  I know when I cook with apples, the recipe books state that if you rub lemon juice on apples it will stop the browning process. Lemons contain vitamin C, which is an acid. What other liquids contain acid?  Think of the content of soda, and water.  Do they contain an acid like lemons or oranges?\n\nI hope this helps.  Try running a search on yahoo with the following search string "apples oxidation"
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Do you mean supercooled substances?\n\nIf so, glasses are the best example and are made by melting a salt and quickly cooling it so that it does not return to its original form.  I don't believe you should have any trouble pointing out the various contributions of glass to our lives.
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I visited Corning Glass at Elmira, NY, home of Steuben Glass.  I believe I learned there (or read it?) that it is easier to make glass by adding sand to molten glass to dissolve the sand than to melt raw sand.  For that reason recycling used glass bottles etc, actually helps the glass industry.  Of course there are many types of glass.  For example, I believe that leaded glass can contain perhaps 40% lead and is crystal clear and easier to etch or cut.  Most common glass is soda glass and can dissolve in water over time.  Antique bottles found in old household dumps are often pitted from groundwater.
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glass has the property to transmit light from one side to the other side of it. other objects stop the light..or atleast do not pass the light fully.. thats why glass is tranparent to the other side
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"Next, the glass begins a heat treatment process in which it travels through a tempering oven, either in a batch or continuous feed. The oven heats the glass to a temperature of more than 600 degrees Celsius. (The industry standard is 620 degrees Celsius.) The glass then undergoes a high-pressure cooling procedure called "quenching." During this process, which lasts just seconds, high-pressure air blasts the surface of the glass from an array of nozzles in varying positions. Quenching cools the outer surfaces of the glass much more quickly than the center. As the center of the glass cools, it tries to pull back from the outer surfaces. As a result, the center remains in tension, and the outer surfaces go into compression, which gives tempered glass its strength."\n\nYes, it increases in strength as it's approx 4x as strong as annealed glass.
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simple it is because of refraction .\nas glass slab is more denser the speed of light is less \nas it comes out of glass into air (less denser than glass)speed increases
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You would find, if you had a sensitive enough measuring system, that the energy is dispersed through the acid as heat. \n\nWhen acid oxidises metal there is an initial activation energy required to break the metal lattice and that energy nromally comes from the heat already in the system. When the lattice is under stress sit requires far less energy to break down and the activation energy is lower. That means that more heat is retained by the system as heat.\n\nYou can see for yourself that a metal lattice under stress breaks down and oxidises more readily by simply bending an iron nail and dropping it in a few mm of salt water for a few days. The iron will rust almost exclusively where it was bent. That is because the  bend represents a point of stress in the lattice.\n\nWith less energy required to break down the metal alttice the overall reaction becomes more energetically positive and the amount of heat in the system increases.\n\nThe amount of additional heat this represents is tiny, but with an incredibly stable atmosphere and a very sensitive thermometer you would regeister the lost energy as a higher temperature than an identical beaker of acid with an uncompressed spring.
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A better safety feature would be to view the chromatogram from behind a sheet of glass.  Glass is opaque to almost all frequencies of UV.
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Glass is more dimensionally stable - it doesn't expand or contract when the temperature changes - and it can be polished to a very smooth surface.   The finish is a very very thin layer of metal.\n\nRead "The Perfect Machine" by Ronald Florence if you want to learn more.
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I got this from my physics prof.  Take a full glass of water, preferably a wine glass, and and some food colouring for the water.  Take a clear piece of acetate and cut it in a circle for the top of the glass.  The piece of acetate needs to be larger in circumference than the glass though.  Place the acetate on top of the glass and turn the glass over.    Explain why the water doesn't escape.  The answer might surprise you.  A hint is because of pressure but how much is there, where does it come from, and what is its dimension?
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"Wood is a complex physical and chemical structure. Its overall elemental composition by mass is about 49% carbon, 6% hydrogen, and 0.2% nitrogen; the remaining elements and their amounts and forms vary considerably from one species of tree to another."  From the Source.\n\nThey want you to say that it is because oxygen is consumed when the match burns.  However, that is wrong.  When the match burns, C and H in the wood is burned to make CO2 and H2O.  CO2 is a gas with the same volume as the O2 from which it was created.  H2O is a gas with TWICE the volume as the O2 from which it was created.  However, the H2O condenses to a liquid that has negligible volume, hence, there is a volume loss.  Notice, though, that wood is only 6% H.  That means that the volume loss due to the creation of H2O is very small.\n\nAlmost all of the volume change occurs because you trap heated air when you put the glass over the burning match.  When the air cools, it contracts.\n\nYou can test this for yourself by rigging a glass with a snuffer inside.  Rig it so that when you put the glass over the match the candle is snuffed out.  Thus, no O2 in the glass is consumed.  The water level will rise as in the case without the snuffer.\n\n(Don't blow out the match then put the glass over it.  This will blow away the heated air that is trapped when you put the glass over a burning match.)
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Common glass contains about 70% silica (amorphous silicon dioxide or SiO2), which is the same chemical compound found in quartz, or in its polycrystalline form, sand. The other two ingredients commonly used in glass are soda (sodium carbonate Na2CO3) and lime (calcium oxide (CaO). Silica must be heated to 2000 degrees Fahrenheitin order to be melted.\n\nIn order to make glass into a lens, lanthanum oxide is added to the mixture to give the lense a gives glass a high refractive index and low dispersion. Most lenses for glasses are not made of glass however, but rather of a plastic known as CR2 or of polycarbonate.
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Because heat causes molecules to separate (expand). The metal lid has a lower liquifying temperature than the glass, and voila! It expands more than the glass, breaking the seal and opening more easily.