Why does ice melt faster in water( at room temp.) than in air?
Asked by:
Vishal.N.Buxani
Answer
Keep in mind that temperature is the average kinetic energy of the particles in a
substance, whereas heat is the total energy of all the particles. The air and
water may have particles moving the same speeds, but the water has more heat
because there are more particles.
Picture it this way. The ice melts as fast moving particles slam into the slow
moving ice particles. As in any collision, some of the energy is transferred to
the ice particle, and with its new energy it can break out of the crystal and flow
as a liquid water molecule.
To make the ice melt faster, you can use hotter (faster moving) particles to slam
into it. This is why the ice melts faster on a hot day than a cold one.
Alternatively, you can just use more collisions. The water is much more dense than
the air, with many more particles per cubic millimeter. Thus even though the water
molecules have the same kinetic energy as the air particles, there are many more of
them hitting the ice each second, and the ice melts faster.
Answered by:
Rob Landolfi, Science Teacher, Washington, DC
'The strength and weakness of physicists is that we believe in what we can measure. And if we can't measure it, then we say it probably doesn't exist. And that closes us off to an enormous amount of phenomena that we may not be able to measure because they only happened once. For example, the Big Bang. ... That's one reason why they scoffed at higher dimensions for so many years. Now we realize that there's no alternative... '