You submerge only the bowl of a metal spoon in boiling water, but when you touch the unsubmerged handle you find it is hot. Explain why this happens in terms of molecular theory.
135435
the heat has been conducted by the metal spoon. the thermal heat energy from the water causes the molecules of the metal to vibrate.  These bump into neighbouring molecules, making them vibrate also until the unsubmerged handle is hot. - conduction
207334
Potential Energy----->Kinetic Energy-----> Heat Energy\n\nIn compressed metal spring, the molecules in the spring comes closer due to pushing and the repulsive force between them is greater than that compared to uncompressed spring.\nSo when the spring is eaten by acid the molecules separate at higher speed than that in uncompressed spring.This extra Kinetic Energy is equal to the Potential Energy stored in compressed spring. The speeding spring molecules collide with acid molecules and this raises the acid temperature.\nThis heat energy is equal to the stored potential energy.
78409
Are you seriously a 4th grader...^\n\nProbably because the liquid may be slightly impure and the only way to get the true boiling point of the liquid is to measure the temperature at the reflux ring.
549299
Yes, in some specific circumstances, hotter water freezes faster than colder water.  All explanations are still hypotheses and there is no fully proven explanation yet for why.  It's known as the Mpemba effect.
433509
heating distilled water for about 10 minutes and then dropping a skittles or something about that size in it...it is \n!!!VERY DANGEROUS!!!DONT TAKE IT OUT OF THE MICROWAVE UNTIL ITS COOLED OFF!!!
281883
If the radiation increases the energy level of the molecule (like boiling water in a microwave oven) heat is transferred.
43159
i believe its because the boiling point of water is only 212 at normal atmospheric pressure, so if the pressure is changed the boiling point does too.
134687
Yes a big problem. Ever hear of the "boiling frog"? If you throw a frog into a boiling pot of water it will freak out, try to escape, and eventually die. BUT... if you put a frog into a cool pot of water turn the burner on and let it reach a boil, the frog will fall asleep in the warming water and then die as it boils. Wake up everybody, we're warming up, don't fall asleep! P.S. all you literal jerks out there.. this is a metaphor. Frogs biologically will respond. If they are able to jump from the container when it heats up, they will. Where are we gonna jump?
1747
Boiling is very rapid evaporation starting at the bottom of a container of water.\n\nEvaporation occurs fastest where there is the most heat (energy).  When we heat water to make it boil we heat it from the bottom so the evaporation occurs at the bottom of the pot.  As a result, large  bubbles of water vapor form at the bottom and rise to the surface in the boiling action.  If we applied the same heat to the top surface of the water it would evaporate just as quickly but we would not call it boiling because the bubbles would not form and rise to the surface.\n\nNormally evaporation occurs at a much slower rate than boiling because most evaporation occurs with room temperature water.\n\nEvaporation-is the escape of molecules from the liquid state to the gas or vapor state. In evaporation, molecules of higher-than-average kinetic energy escape from a liquid, leaving it cooler than it was before they escaped.\n\nBoiling-is the temperature at which the vapor pressure of a liquid is equal to the \nexternal pressure above the liquid.  When we give the boiling point of a liquid, we \nneed also to state the pressure.
324724
The body regulates our internal temperature in reference to an outside source (in this case the warm water). Your blood vessels going to your extremities are dilated, you sweat slightly more, and in some cases metabolism decreases because it produces heat. \n\nBy the way, the water does cool when it comes in contact with our body. The first thing that happens is it evaporates, because it uses the heat from our body to go from a liquid to a gas (evaporation). Then, it condenses (goes from gas to a liquid) back down to the bathtub because the air temperature is cooler than our body.
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There may be certain conditions in which two beakers of water, one at a higher temperature, put into a freezer together, will freeze with the originally hotter one freezing first. It only happens under certain conditions, and is NOT generally true. Apparently the hotter one can develop stronger convection currents in the beaker due to it's initially hotter temp and increased evaporation at the surface, and the continued movement of the water due to the currents set up initially will allow faster heat transfer as it cools.\n\nIt is called the "Mpemba effect".
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This is very similar to the floating of a (slightly oily) needle on the water. Surface tension acts like a stretched elastic membrane. The water is always trying to minimize its free surface area (that is, surface that is not contacting and wetting some solid).\nWhen you put an unwettable object on the water it stretches the surface which increases the surface tension. This tension holds up the needle. When you push a tube with an unwettable inner surface into the water, the surface tension tries to minimize the unwetted surface area by not rising into the tube. It will reach a level in the tube that balances the bouyancy due to the immersed air with the surface tension.
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It's bernoulli's principle. Fluids have a lower pressure when moving than when still. Since the water is moving past the spoons (which act like the wing of a plane) they feel a pull from the pressure drop and come together. Try it with a peice of paper sometime. Roll a piec of paper up so when you place it on a flat surface it looks like a curved bridge. then blow under it and it will collapse instead of blow away. It's pretty neet.
343402
its the same concept when comparing a cup of 100 degree coffee to a hot tub filled with 100 degree water.  the hot tub is hotter because even though the temperature is the same the total heat and energy in the hot tub is greater.  remember that heat measures the total energy of the substance and temperature is just the average kinetic energy.  since there is more substance in then hot tub there will be more heat.
397419
Water that is evaporating is not the same as water boiling. evaporation is the loss water from the surface that is still water in very small amounts that become suspended in the air. Boiling that occurs at 100c is a state change in the water where the bonds in the water lattice have been broken. The steam then coming in contact with the cooler surrounding air then rapidly cools and forms water droplets on cooler surfaces or in the air and just like fog is a saturation of the air with water and you can see it so you also can see the steam re condensing into water in the air.
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All molecules above absolute zero (0 Kelvin or approximately minus 273 degrees Celsius) have some form of heat energy (aka enthalpy).  This is distributed over four different types of "motion".  These are known as Translational, Rotational, Vibrational and Electronic.  To effect each of these takes increasing amounts of energy   \n\nYou've asked about Translational energy.  Heat energy gets converted to kinetic energy.  When there is insufficient kinetic energy (ie: too cold), molecules remain as solid (frozen) in a lattice. Once the melting point has been reached then the molecules have enough kinetic energy to break from their solid structure and can move freely about one another (liquid).  If enough heat energy is applied that individual molecules have enough energy to escape one another, then they boil off and become a gas.  Different gases have different boiling points.  Water boils at 100 degrees Celsius to become steam.  Nitrogen boils at something like minus 170 degrees Celsius.  So, at Standard Temperature and Pressure, 298.15K (25 degrees Celsius) and 760mmHg (1 Atmosphere), Nitrogen is roughly 200 degrees above boiling point.  This is why it can move so fast.\n\nRotational Energy: As the name suggests, energy required to spin a molecule about an axis such that, while spinning, it changes orientation (ie: N2 is a linear molecule so spinning on the axis along the triple bond doesn't count).\n\nVibrational Energy: Energy spent bending molecules (they do that too!)\n\nElectronic energy: this one is less motion of the molecule than of the electrons jumping orbitals.  Electronic energy is responsible for things like fluorescence and, if too much energy is applied to a molecule then the bound electron can escape and break the bond (resulting in degradation of the molecule).
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water "boils" when the Kinetic energy (energy of motion and heat) cause the molecules of water to expand or separate far enough away that it changes from a liquid to a gas. The greater the force keeping the molecules together, the more energy it needs. On Earth, the force is air pressure. At sea level where the pressure is greatest, water boils at about 100 degrees Celsius. Up in the mountains at 7000 feet it would boil at 80 -90 degrees or even less. In space even the smallest amount of energy would cause it to "boil".\nIt takes one calorie to raise one gram of water one degree Celsius. If you trap the water in a container, you can get the heat of the water much higher than the boiling point. But it could explode if the container is too weak to handle the pressure. So don't try it.