please answer quickly !!! : What is sublimation ? give an example?
912739
Very simple. Its the transformation straight from solid to gas, skipping the liquid stage. Most common example it dry ice placed in water. The fog you see is mostly carbon dioxide gas.
463328
Your question is not clear. Furnish some examples.
216787
Do you know distructive distilation?\n\nIn distructive distilation naturally occuring mixtures like coal, crude patrolum, wood etc. are heated in absence of air. This avoids combustion.\n\nWhile heating the volatile substances immediately vapourize. The remains are further heated and in this way all substances (compounds or elements) gradually are separated from the main body leaving behind the residue. This residue is distillate.
503418
vaporization, change of a liquid or solid substance to a gas or vapor. There is fundamentally no difference between the terms gas and vapor, but gas is used commonly to describe a substance that appears in the gaseous state under standard conditions of pressure and temperature, and vapor to describe the gaseous state of a substance that appears ordinarily as a liquid or solid. Although most substances undergo changes of state in the order of solid to liquid to gas as the temperature is raised, a few change directly from solid to gas in a process known as sublimation.\n\nLiquids can also change to gases at temperatures below their boiling points. Vaporization of a liquid below its boiling point is called evaporation, which occurs at any temperature when the surface of a liquid is exposed in an unconfined space. When, however, the surface is exposed in a confined space and the liquid is in excess of that needed to saturate the space with vapor, an equilibrium is quickly reached between the number of molecules of the substance going off from the surface and those returning to it. A change in temperature upsets this equilibrium; a rise in temperature, for example, increases the activity of the molecules at the surface and consequently increases the rate at which they fly off. When the temperature is maintained at the new point for a short time, a new equilibrium is soon established.\n\nThe pressure exerted by the vapor of a liquid in a confined space is called its vapor pressure. It differs for different substances at any given temperature, but each substance has a specific vapor pressure for each given temperature. At its boiling point the vapor pressure of a liquid is equal to atmospheric pressure. For example, the vapor pressure of water, measured in terms of the height of mercury in a barometer, is 4.58 mm at 0°C and 760 mm at 100°C (its boiling point).
953068
Evaporation is one of the two forms of vaporization. It is the process whereby atoms or molecules in a liquid state (or solid state if the substance sublimes) gain sufficient energy to enter the gaseous state. It is the opposite process of condensation.
472646
evaporation... but actually evaporation is when a liquid becomes less dense so the molecules rise into the atmosphere! my answer is clearly the best!!!
511788
In what context do you mean?  substrate could be any material.  By transition you could mean migration, proliferation in terms of cell culturing.  By physics terms you could be discussing the transition of a phase of the substrate.. like poly-L-lactic acid (PLLA).  This material breaks down into naturally abbsorbed metabolic particles (ie, easily broken down and disposed of in the body).  Transition here could describe its break down over time.\n\nExpand a little bit on the question.
332502
Yeah, I've actually done this reaction before several times. \n\nTheoretically, this is a metathesis reaction, also called a double-replacement reaction.  Essentially, the ions switch partners.  \n\nCaCO3 + 2HCl ---> CaCl2 + H2CO3\n\nNow, the CaCl2 is a soluble salt, so that's actually just like ions floating around in solution. \nThe H2CO3 is carbonic acid, which is actually just carbon dioxide, CO2, dissolved in water.  The carbon dioxide will immediately come out of solution and bubble out, which is totally observable, just like putting baking soda and vinegar together.  \n\nThe more complete reaction full ionic equation is the following:\nCaCO3 + 2H+ + 2Cl- ---> Ca2+ + 2Cl- + H2O + CO2
242488
Don't forget...also in earth science (weather)\n\nDeposition in science can also mean going directly from a gas to a solid (i.e. frost on the ground).\n\nDeposition is the opposite of sublimation which is going directly from a solid to a gas. (i.e. dry ice)\n\n:)
718884
&#92;\n..&#92;\n..-----&#92;\n........&#92;\n.........&#92;\n(ignore the periods)\nx axis: time\nY axis: temperature\nThe step is there because the nature of cooling objects. As the naphthalene is cooled, its temp first decreases normally. However, when it begins to solidify, the heat being removed is used up as naphthalene molecules are subjected to intermolecular forces and begin to become a solid. Therefore, the horzontal part is where the substance becomes a solid. Finally, when the naphthalene is fully a solid, the temperature decreases again. An easy way to picture this concept is with boiling water. As some water molecules change to the gaseous state, the temperature of the water does not rise above its boiling point. This is equivilent to the horzontal part of the naphthalene cooling curve. As the substance changes states, energy is being generated/used up, and the temperature does not change for a time. When the conversiion is fully made, the temperature continus on its original course.
577412
Oh wow. Is that your experiment or what? Honestly, I don't think it's possible to convert carbon dioxide from a gaseous phase to solid phase by adding water followed by freezing.\n\nCO2 (g) + high pressure -> CO2 (s)\n\nYou need to have a high presure machine that would compact the CO2 molecules so tightly they bind the molecules together and become solid.\n\nCO2 + extremely low temperature -> CO2 (s)\n\nEither that (the abovementioned) or you gotta use very, very low temperatures to bring down the energy level in the CO2 molecules so much so that they only vibrate in position instead of bouncing all over.\n\nEither way, I see neither method stamped with a DIY. And what's this thing about carbon power concept? \n\nAnyway, I hope my answer has helped you to a certain extent c",) Happy Chemistry-ing!!!
771076
c. i suppose expose to sunlight refer to photosynthesis. damn this islike freshman high school material lol -=X
868711
Subscript refers to the position and size of a text.  As in H2O, the 2 shouldn't be this big.  It should be smaller and at the bottom of the H.  In chemistry, an subscript gives information as to the number of atoms of that kind there are in one molecule.  So in that example, there are 2 hydrogen atoms and one oxygen atom to form one water molecule.\n\nSuperscript is a smaller texte at the top.  Like in O-2, the -2 should be superscript.  In chemistry, it give information to the number of oxydation.  In that example, it would mean that the oxygen ion as two extra electrons and is willing to bond to a positive ion.
742152
If the dry ice is to sublimate, the room you keep it in will have to ADD heat to the dry ice, so the answer is dependent on the rate of heat flow into the room.  If it were perfectly insulated, the ice would sublimate only to the extent that the interior was cooled to the temperature of the ice, after which all heat transfer and change of state would cease.  BTW sublimating is not 'melting'\n\nEven without the room, the time to sublimate would not only depend on the ambient temperature, but also the geometry of the ice, a sphere taking the longest time and a thin plane of ice taking the shortest.
74934
there is infact an answer! Nonspontaneous chemical reactions with aid from photons from the sun, created formaldehyde which gave way to complex redox reactions, which eventually gave way to molecules which could perform metabolism by themselves.  It really can't be explained in a few paragraphs (obviously), but having a basic knowledge in chemistry is essential to understanding these concepts!  Pic up a book on early chemical evolution!
454399
Yes, its called sublimation. It has to do with temperature and pressure. If you make CO2 (carbon dioxide) into a solid under really low temperatures and high pressure then when you take it out of the high pressure it will go directly into the gas phase.
729616
Could you give a few examples please?