Why is CO2 a gas at room temperature & SiO2 a solids?
97128
This is a classic result of intermolecular forces.  \nCO2 is a nonpolar molecule, meaning that molecules of CO2 have very little attraction between other molecules of CO2, so they like to be separate and just float around as gases.  (The only intermolecular force affecting CO2 is London dispersion, the weakest one.)  \nSiO2, on the other hand, is a network solid, which means that each unit of SiO2 is covalently bonded to another SiO2 unit, and covalent bonds are always stronger than any intermolecular force.  That's why it's a solid.
930214
solid to gas is endothermic reaction as it absorbs energy\ngas to solid is exothermic as it give off energy
598488
Solid.  If the temperature is below the melting point, then it will be a solid.  Unless you want to get into changing pressures, or something.
1021437
a) \n\nThe molecules in a substance are in constant motion. Now there are two oppposing forces on a substance. One is the intermolecular bond energy that tries to keep the molecules together. The other is the kinetic energy of the molecules that tries to push the molecules apart (these two forces work together to keep substances in equilibrium - basically keeps it from exploding or imploding in simple terms).\n\nNow, in solids, the molecules have low kinetic energy but high intermolecular bond energy(IBE). Liquids, the kinetic energy is higher and conversely the IBE is lower. Gases, the kinetic energy is high and the IBE is low (makes sense - the "bond" is weak)\n\nSo now, the kinetic energy or molecules is directly proportional to the heat applied - the hotter it is, the more kinetic energy the molecules have. Therefore when you heat it ... the kintic energy gets stronger and stronger and the IBE gets weaker and weaker until it breaks and the substance undergoes its change of state.\n\nHope this explained it well!
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!!!
1122084
Pure silica (SiO2) has a melting point of about 2000 °C (3600 °F), and while it can be made into glass for special applications (see fused quartz), two other substances are always added to common glass to simplify processing. One is soda (sodium carbonate Na2CO3), or potash, the equivalent potassium compound, which lowers the melting point to about 1000 °C (1800 °F). However, the soda makes the glass water-soluble, which is usually undesirable, so lime (calcium oxide, CaO) is the third component, added to restore insolubility. The resulting glass contains about 70% silica and is called a soda-lime glass. Soda-lime glasses account for about 90% of manufactured glass. The only glasses that do not include silica as a major constituent are the Chalcogenide glasses, used for fiber optics and specialized technical applications.
754768
Carbon at room temperature and pressure is a solid, not a gas. If you raised its temperature enough to make it a gas, it would become highly reactive and would be too hot for you to breathe.
324162
Deposition is the answer.  Sublimation only refers to the process of solid going to gas.
174818
Its all about shape and volume.  Solids have a set, defined shape, and a set volume.  Liquids have no defined shape, but a set volume, and gas has no set shape nor a set volume.  Those two things define whether or not something is solid, liquid, or gas.
311127
maybe its inside or core is solid and as big as the earth's moon. But the whole of it is gaseous
948057
Room temperature Seems like a trick question to to unless they are asking what physical state it is in at room temperature then that would be solid
957050
all things have a solid liquid and gas state. it just depends on the temperature.
762753
The interactions between the carbon dioxide molecules are stronger, and thus it forms a solid at a higher temperature.\n\nIn water, the attractions are even stronger and you only need to go to zero degrees to get a solid. If you go to 100 degrees water becomes a gas. (temperatures in celcius)\n\nSimilarly for other molecules, if the atrraction between them is strong you get solids and liquids at higher temperatures than for less cohesive molecules.
943424
Oxygen itself is a gas of course.\nIn most kind of crystals you find oxygen atoms (or ions).\n\nTh
568153
When you change a gas directly to a solid (in your example, crystals) is called deposition. An example of this is frost on the grass. The water vapor becomes ice & is deposited directly onto the grass blades.\n\nSublimation is going directly from a solid to a gas w/o going through a liquid phase. An example of this would be dry ice. It goes directly from the dry ice to carbon dioxide gas.\n\nMany times sublimation is used interchangebly for both but the correct term here would be deposition.
852036
It's called vapor deposition.  Sublimation is when a solid goes directly to gas.
445028
Carbondioxide gas, Oxygen gas and Nitrogen gas