ice melts quicker in water than in sunlight but temperature of water is lower. why?
367774
Water is denser than air (or sunlight).
434026
If you place a glass of hot water in an ice box it will actually freeze faster than a glass of cold water. \n The reason is that the temperature difference makes the water circulate in the warm glass transfering the heat loss evenly through the contents, in cold water the outside freezes first which insulates the inside from heat transfer keeping the center liquid.\n Try it, you'll see.
1142972
In short, ice float in water because it is less dense.\n\nDensity = mass / volume\n\nFor a more thorough explanation, one needs to look at what happens when liquid water freezes into solid water (ice).\nAs the water freezes and becomes a solid, it expands.  The volume of a given mass of water becomes larger, therefore the density decreases.  Without going into the effects of buoyancy to explain "why" less dense things float (the weight of the fluid they displace is greater than the weight of the object), just accept that they do.\n\nTo be even more thorough,\nWater expands when it freezes because of the strong, "Hydrogen bonding", intermolecular forces which exist between the water molecules in the liquid/solid.\nWhen water is a liquid, the molecules have much more freedom to move around and rotate any way they please, but when the water freezes into a solid, the molecules have significantly less energy (thus less freedom to move around) and try to take on the most stable/low energy state they can...which happens to be in a lattice structure which has a higher volume that when the molecules were in the liquid state.  So it is because of the Hydrogen bonding present between the water molecules that solid ice float in liquid water.
337101
Ice is less compact or less dense than liquid water.
1036867
Of course ice and water are chemically identical consisting of H2O.  The two hydrogen atoms attach to the oxygen atom other than in a straight line (not like beads on a string).  The electron field surrounding the water molecule is uneven providing it with a "polarity" that makes it much easier to pack many molecules together in a given (rather than arbitrary) arrangement.  When water is a vapor (or steam) there is so much vibrational energy that the molecules bounce off each other maintaining a "pressure" depending on their energy (temperature).  When the molecules are a liquid, they are very closely packed and are nearly incompressible (even seven miles below the surface of the ocean!).  The bulk water expands and contracts only a little with temperature changes.  When heat is removed from the water (in a freezer?) the molecules are attracted to each other in a preferred array due to polarity and form long chains of molecules that use up space far less efficiently.  The "ice" is less dense and floats on water because the space between chains is filled with a vacuum or gases that weigh very little.  When the water is allowed to freeze in open space (a cloud?) the polarity is free to align water molecules in the most preferred orientation; a six sided snow flake.  When hoar frost forms on a cold window pane the ice forms in dendrites, like growing Christmas trees.  Hope that helps a little.
726971
h2o has a higher specific heat, meaning it takes a greater amount of energy to change the temperature of the h2o than the metal.  That is why it takes a long time for lakes to freez, ect.
46526
it doesnt, however the energy is lost faster in hot water than in cooler water.  The rate at which all water freezes is the same.
160755
depends what depth.\nAt surface around -2degC\ndeeper you go (especially below the halocline) the warmer you get. -2degC is possible because the salt in the water lowers the melting point of ice to ~ -4degC.
236269
Because the atoms in heated water are farther apart.  It actually makes the water less dense.  It then becomes easier to freeze less dense liquid.
135812
Well for an eight year old....(sounds like an intelligent one to me though)... The reason water freezes slower is because the particles of salt and sugar get in the way of water making a ice crystal.  Salt takes longer because when dissolved it "ionizes" or breaks apart into 2 particles while sugar remains as one.  Salt having two particles it is able to disturb more molecules of water from making ice crystals. I hope that helps! It excites me to here a child of such a young age interested in such things.
628194
It decreases ever so slightly.\n\nFrozen water has a larger volume than liquid water (this can be inferred from the fact that it is less dense; alternatively you can show it is less dense if you know it has a bigger volume), so as more water goes from solid (ice) -> liquid (water), the total volume decreases.\n\npeople have been saying it increases; this is incorrect! When you put water in a cup and leave it in the freezer, the cup breaks. This is because water EXPANDS as it turns into ice; therefore it will CONTRACT when it melts.
457329
This has to do with the optical properties of water as it enters a new so-called phase; from liquid to solid. The liquid and solid state of water are two macroscopic phases, which means that the collective behaviour of the water molecules changes drastically as the temperature, in this case, drops below T = 0 degrees Celsius. As the molecules behave differently in the solid state than in the liquid state, e.g. they reflect light in a different manner due to their structural arrangement, it is not surprising that water has a different color when it freezes compared to when it is a liquid.
252337
The figure I have from a university course was 45m (roughly 80ft).  You can discount any ice floating on the sea, such as the North Polar icecap,the large ice shelves around Antartica and the sea end of glaciers as they havealready displaced the equivilent amount of water already (imagine a glass fullof ice and water, as the ice melts the glass does not overflow).\n\nIf all the ice were to melt the rise would not actually be directly equal to the amount of water resulting due to differences in the densities of salt and freshwater.  Taking the temperature into account the molten ice would be denser than the warmer saltwater so reducing the overall rise.
527105
Water when frozen, expands.  it is less dense. so it floats on water which is more dense.
204871
The answer is D.  Since ice forms a complex crystalline structure instead of some amorphous solid, it is one of the only elements whose solid form is less dense than its liquid form.  This is why ice floats.  This is important biologically.  If ice did not float, it would destroy the ecosystems underwater every winter.
685263
as you know the density of ice and water is slightly different.\n\nmultiply the height by the ratio of densities, i.e. density of water/density of snow.\n\nIce has a density of 0.917 g/cm³ at 0 °C, whereas water has a density of 0.9998 g/cm³ at the same temperature
807422
When water freezes, it expands because the molecules form into a crystal lattice. The expansion causes ice to be less dense than liquid water and as a result, it floats.