0
votes
1answer
46 views

Thermal Velocity

What is thermal velocity? What is it's physical significance? Wikipedia says: The thermal velocity or thermal speed is a typical velocity of the thermal motion of particles which make up a gas, ...
2
votes
1answer
53 views

How fast do molecules move in objects?

I guess it depends on the heat or the type of the material but can you give some examples or formulas to calculate it ? The best example would be the average speed of the air molecules (all types in ...
7
votes
3answers
433 views

Hot water freezing faster than cold water

This question has puzzled me for a long time. There is already a question like this on Physics.SE. John's answer to the question seems quite satisfying. But when I googled the cause I found this and ...
0
votes
1answer
30 views

Air vs. Water attraction of Oxygen Molecules

The air we breathe is made up of nitrogen and oxygen gases. The water in a pond is made of a single hydrogen/oxygen molecule. If it wasn't for the surface tension on top of the water, oxygen molecules ...
9
votes
4answers
346 views

Can we detect whether food has previously been heated in a microwave oven?

An acquaintance told me that she refuses to eat microwaved food because she read that the microwave changes the molecules of the food somehow. Her statement is vague and her sources are dubious but I ...
0
votes
4answers
148 views

Is vapour pressure based on partial pressures or just total pressure on the liquid?

The explanation for the boiling point of water is that at 100C, the vapour pressure becomes greater than atmospheric pressure. But say you had a a jar of water sealed in argon at 1atm, which is larger ...
0
votes
2answers
58 views

Molecules of a solid [closed]

Question: Molecules of a solid : (a) are always in a state of motion (b) move only when heated (c) move because they are loosely bound (d) do not move at all My attempt: I ...
5
votes
4answers
382 views

Water in vacuum (or space) and temperature in space

So, water in vacuum will boil first and then freeze. I don't know how the freeze happens. As pressure lowers to zero, what happened to freezing point? (I know heat taken by vapor, and the water cool ...
6
votes
4answers
642 views

Can a single molecule have a temperature?

A show on the weather channel said that as a water molecule ascends in the atmosphere it cools. Does it make sense to talk about the temperature of a single molecule?
2
votes
2answers
696 views

Why is there a Global Minimum for the Morse Potential?

For Diatomic molecules, the Morse potential describes their potential energy as a function of separation distance between the two particles. My question is, what is the explanation of of the dip ...
3
votes
1answer
195 views

What's the underlying particle physics of endothermic reactions?

I don't just mean reactions that require heat to proceed, storing surplus energy in chemical bonds. I wonder about strongly endothermic reactions that suck heat out of environment. You take some ...
6
votes
1answer
372 views

Gas kinetic representation of trans-critical conditions

From a molecular point of view, can we think of the super-critical conditions as conditions where T and p are large enough that the collisions of gas molecules are frequent and powerful enough to ...
-2
votes
3answers
373 views

What forces are at play when molecules wiggle (due to heat)?

What forces are at play when molecules wiggle (due to heat)? Or in other words, What makes them move?
3
votes
3answers
2k views

Does stirring water in a bucket in whirlpool keeps it warm?

I did an experiment when I was a teenager. I want to prove/see what really went on in that experiment. When taking a bath, take a warm water in bucket and start taking a bath. You will notice that ...