aommaster Posted December 8, 2003 Posted December 8, 2003 How can water exist in its 3 states solid= cause where it exists is under its melting point, its frozen Liquid= Cause where it is is above its melting point gas=??? Why? or the question may be HOW?
blike Posted December 8, 2003 Posted December 8, 2003 Look up the definition of liquid. Gas is above the boiling point. You know, steam.
blike Posted December 8, 2003 Posted December 8, 2003 erm, look up gas, and how things become gaseous.
Skye Posted December 8, 2003 Posted December 8, 2003 Are you asking why there are seperate phases? The phases properties are formed by the different interactions between the molecules. Phase changes occur at a certain corresponding pressures and temperatures. As the molecules are brought closer together by lower temperature or higher pressure, intermolecular forces and bonding occurs. Gases are pretty much free of intermolecular forces as they are usually so far apart. Liquids are held together by van der Waals forces (ion-dipole, dipole-dipole and London dispersion forces) and hydrogen bonding. Solids can be bound by the same forces as for liquids, also by covalent bonds, ionic bonds or the delocalised electrons in metals. With H2O there is lots of hydrogen bonding in the liquid phase, but in ice it forms a lattice of hydrogen with long bond lengths which is why it is less than dense than water.
aommaster Posted December 8, 2003 Author Posted December 8, 2003 no, i know gas is when something goes above boiling, but people say that there is water vapour (steam) how come since nowhere is 100 degrees C
wolfson Posted December 8, 2003 Posted December 8, 2003 At 100oc water boils and evaporates into the air, at 100oc all the bonds are broken which link the molecules in water (l), however even below 100oc some evaporation from water surfaces occurs, with water molecules “breaking” free and escaping into the air. These water molecules that have “broken” away are named as water vapour. Water vapour enters the atmosphere by evaporation of water, i.e. lakes and rivers, water may also enter the atmosphere by transpiration from plants and trees, that’s why water vapour occurs below 100oc.
YT2095 Posted December 9, 2003 Posted December 9, 2003 if you watch a boiling kettle, the spout will have an area that is clear directly above it, that is Gaseous water (steam) then just above that you`ll see what`s mistakenly called Steam, in fact that`s re-condensed water vapor. Steam is invisible
aommaster Posted December 9, 2003 Author Posted December 9, 2003 oh. ok thanx for the info this was just out of curiosity
NSX Posted December 10, 2003 Posted December 10, 2003 YT2095 said in post #8 :if you watch a boiling kettle, the spout will have an area that is clear directly above it, that is Gaseous water (steam) then just above that you`ll see what`s mistakenly called Steam, in fact that`s re-condensed water vapor. Steam is invisible Why can we see water vapour?
NSX Posted December 10, 2003 Posted December 10, 2003 Dudde said in post #11 :because Dudde said so. Right?
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