Understanding Different Energy Types: A Comprehensive Guide

[mather]

hello!

I would like to know, which are all the energy types, force types, field types, wave types, particle/material types?

i ask this, because i was told recently that van der walls forces/field/energy is not electric (either electrostatic or electromagnetic)

thanks!

 

[Bobbywhy]

mather, I think you don't need anyone to list "all the energy types, force types, field types, wave types, particle/material types" to get answers. For a clear overview of Van der Waals forces have you studied this yet?
http://en.wikipedia.org/wiki/Van_der_Waals_force

If you learn everything on this page you can get to more detailed explanations by clicking on those "blue" (links) terms within the article and also by using the references at the end.

There are lots of other sources of explanations using "Google" search.

 

[mather]

I still can't get it.
What else can be, if not gravity, electricity, electromagnetism?

 

[Drakkith]

I still can't get it.
What else can be, if not gravity, electricity, electromagnetism?

Kinetic energy, thermal energy, electrical energy, and a dozen other terms. All of it really boils down to the 4 fundamental forces. We just use more terms to refer to specific examples of energy to make it easier to work with.

 

[Bobbywhy]

mather, I am not an expert, but as I read these sources it seems that the van der Waals forces are indeed mediated by electrical fields...both attraction and repulsion.

“van der Waals forces
The attractive or repulsive forces between molecular entities (or between groups within the same molecular entity) other than those due to bond formation or to the electrostatic interaction of ions or of ionic groups with one another or with neutral molecules. The term includes: dipole–dipole, dipole-induced dipole and London (instantaneous induced dipole-induced dipole) forces. The term is sometimes used loosely for the totality of nonspecific attractive or repulsive intermolecular forces.”
http://goldbook.iupac.org/V06597.html

Here are a few more websites for you to study:

http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/waal.html
http://www.chemguide.co.uk/atoms/bonding/vdw.html
http://antoine.frostburg.edu/chem/senese/101/liquids/faq/h-bonding-vs-london-forces.shtml

Finally, here is an easy to read and excellent description of the van der Waals force:
http://www.britannica.com/EBchecked/topic/622645/van-der-Waals-forces

 

[mather]

Finally, here is an easy to read and excellent description of the van der Waals force:
http://www.britannica.com/EBchecked/topic/622645/van-der-Waals-forces

in deed this is excellent and concise

the question is... do I miss something that I still think these forces are due to electric charged subatomic particles, thus they are electrostatic/electromagnetic?

 

[Studiot]

Mather,

Perhaps if you posted the exact nature of what you were told?

Did you respondent mean that Vander Walls and (London) forces are the result of statistical averages of short term electrical interactions, in much the same way that pressure is the result of short term momentum interactions in gasses?

Or did she mean that the Van Der Walls equations was the first to recognise that a correction to the ideal gas equation was necessary to acount for the fact that molecules occupy space?

Or...?

 

[mather]

Mather,

Perhaps if you posted the exact nature of what you were told?

Did you respondent mean that Vander Walls and (London) forces are the result of statistical averages of short term electrical interactions, in much the same way that pressure is the result of short term momentum interactions in gasses?

Or did she mean that the Van Der Walls equations was the first to recognise that a correction to the ideal gas equation was necessary to acount for the fact that molecules occupy space?

Or...?

sorry but this is not the english i can comprehend

 

[Studiot]

ask this, because i was told recently that van der walls forces/field/energy is not electric

Please post exactly what was said.

 

[mather]

Please post exactly what was said.

That van der wals are not electric forces.
There is a possibility that he said van der wals are not electrostatical or maybe electromagnetical forces.

 

[Studiot]

So do you understand the kinetic theory of gasses about how the pressure on the walls comes about?

 

[mather]

So do you understand the kinetic theory of gasses about how the pressure on the walls comes about?

I suppose it is because of the thermal/Brown movement of the molecules of the gas.

I don't know what is the source of that kinetic energy. I know that it increases with heat. But I don't know the quantum/submolecule mechanism of it.

 

[Studiot]

The kinetic theory is not a quantum or any fancy upmarket theory.

It is just about representing the molecules as little balls bouncing around.

As they bounce around they will bump into each other and into the container walls.

As they bounce around they have a range of velocities and the velocity of individual molecules changes as they bump into things.

As with any range of quantities we can represent this by an average velocity.

Bumping into each other only causes changes within the gas so we are not interested in that here.

Bumping into the walls, however, exerts a force on the walls. the greater their velocity the greater their impact force.

Since there are lots of molecules we can calculate an average force using the average velocity.

We call this average force the pressure.


The point of all this is that we can attribute the pressure of say 5 pascals to the average effect of the momentary bumping of the molecules into the walls.

I hope this helps because VDW forces have a similar average basis which we can move on to.

 

[The_Duck]

i ask this, because i was told recently that van der walls forces/field/energy is not electric (either electrostatic or electromagnetic)

That's wrong; Van der Waals forces are indeed electromagnetic.

 

[mather]

Okay then I understand that van der wals are actually electromagnetic forces

Their source is the movement of electrons around the nuclei of a molecule, which movement makes the molecule be a specific dipole, tripole, etc (according to the structure of the molecule) at a specific time.

As for thermal energy, how does it increase the kinetic energy of a molecule?

Which is the velocity of a molecule in void or where there is no thermal energy at all?

 

[Studiot]

I don't know what to say since your response doesn't seem to have anything to do with my last post.

Am I wasting my time?

 

[mather]

No, i thought that i understood you and i said what i exactly understood in my last post, isn't it correct?

As for heat and molecular velocities, maybe it's another topic

 

[Studiot]

The only point I wanted to carry forward was that pressure is an average result of the variable random actions (motions) of a great many molecules. Because it is an averaging process it is statistical in nature.

Are we OK with that?

 

[mather]

yeah, it seems alright

 

[Studiot]

Ordinary chemical bonds are fixed
in length
in direction
in strength

eg the oxygen to oxgen bond in the O₂ molecule.

The bonding electrons are shared equally between each oxygen atom.

If the two atoms are different eg oxygen and hydrogen in water there is a slight shift of the bonding electron from the hydrogen towards the oxygen.

We say that the oxygen has greater electron affinity than hydrogen.

There is a slight unequal sharing of the electron.

This leads to a permanent small negative charge near the oxygen atom and a corresponding small positive charge near the hydrogen.

The small negative charge on one molecule interacts with the small positive charge on another molecule.

This is observed as an intermolecular force we call hydrogen bonding.

Hydrogen bonding is much weaker than ordinary bonding and is not fixed in length, or direction. Hydrogen bonds come and go as the molecules whizz about.

But the average effect is as if there were extra weak bonds between the molecules.


Now consider what a molecule 'sees' as it approaches another one.

We can use the Bohr model of electrons orbiting a nucleus for this purpose.

If the electron is on the same side of the molecule as the approaching one it will see a negative charge.

If the electron is on the opposite side of the molecule as the approaching one it will see a positive charge. (a nucleus)

Either way there will be an electric interaction of varying stength.

We call the average of all these interactions Van der Waals forces.

At greater range they are London forces.

Yes a more sophisticated way to look at this is to note that the orbiting system forms variable dipoles which interacts with each other.

That's a lot to chew on, so I'll leave it at that for tonight.

 

[mather]

great, thanks!

 

[Studiot]

So either the person who told you that VDW etc forces etc are not electric

was just plain wrong.

or

He was talking about something else.

or

He meant that the force is not a large single constant direct electric force like a chemical bond, but an average of lots of short term small (electrical) effects, but did not explain this very well.

I suggest this is a bit like saying that pressure is not a large single constant force but the average of lots of small short term forces.

 

[mather]

It can make sense that way

Something else, can heat transfer through void?

Can there be an atom in total zero?

 

[Drakkith]

It can make sense that way

Something else, can heat transfer through void?

Only by EM radiation.

Can there be an atom in total zero?

I don't know what this means.

 

[mather]

Can an atom exist in absolute zero temperature?

 

[Drakkith]

Can an atom exist in absolute zero temperature?

Of course. Absolute zero is simply the minimum energy state that a material can be in. It cannot decrease in temperature any more because there is no more energy for it to give up.

 

[mather]

I bet the atom will blow up

its energy will dissolve in the environment

 

[Drakkith]

I bet the atom will blow up

What possible reason would the atom have for blowing up?

its energy will dissolve in the environment

Energy does not have the capability of doing that. Energy is not a "thing", it is not a "substance". Just like a particle can have a velocity, a system of particles can have energy. Energy in it's simplest definition is simply the ability for one system to perform work on another system. That is, the ability of one system to change another system in some way.

 

[mather]

the energy of the atom (ie. the potential energy between electrons and protons, the kinetic energy of electrons, etc), will be transferred to the environment, because of the second thermodynamics law

that's why the atom will simply decay

 

[mather]

the energy of the atom (ie. the potential energy between electrons and protons, the kinetic energy of electrons, etc), will be transferred to the environment, because of the second thermodynamics law

that's why the atom will simply decay

any comment?

 

[Drakkith]

the energy of the atom (ie. the potential energy between electrons and protons, the kinetic energy of electrons, etc), will be transferred to the environment, because of the second thermodynamics law

that's why the atom will simply decay

any comment?

This is incorrect, the atom will not transfer it's energy into the environment simply because it is in it's ground state.

 

[mather]

This is incorrect, the atom will not transfer it's energy into the environment simply because it is in it's ground state.

how can the energy of a proton and an atom in infinite distance (thus zero potential energy and zero kinetic energy) be larger than the energy of the hydrogen atom (where there is potential energy and kinetic energy)?

 

[Drakkith]

how can the energy of a proton and an atom in infinite distance (thus zero potential energy and zero kinetic energy) be larger than the energy of the hydrogen atom (where there is potential energy and kinetic energy)?

If we separate a proton and an electron by a HUGE distance in an empty universe, they will have maximum potential energy. Upon coming together, this potential energy is released in the form of EM radiation and the atom now has less energy than the proton and electron did before.

 

[mather]

If we separate a proton and an electron by a HUGE distance in an empty universe, they will have maximum potential energy. Upon coming together, this potential energy is released in the form of EM radiation and the atom now has less energy than the proton and electron did before.

I think they won't be able to interact, if they are separated in such a huge distance

their electrostatic fields have some finite diameter, haven't they?

 

[Bobbywhy]

the energy of the atom (ie. the potential energy between electrons and protons, the kinetic energy of electrons, etc), will be transferred to the environment, because of the second thermodynamics law

that's why the atom will simply decay

mather, when you make statements like the above you must be prepared to provide some accepted sicientific evidence. In this case, you have provided none, only your own statement, "because of the second thermodynamics law." But that's not enough. You must explain the mechanism or process.

Cheers,
Bobbywhy

 

[Drakkith]

I think they won't be able to interact, if they are separated in such a huge distance

their electrostatic fields have some finite diameter, haven't they?

No, the EM field has infinite range.

 

[mather]

If we separate a proton and an electron by a HUGE distance in an empty universe, they will have maximum potential energy.

this is wrong:

potential energy is inversely (and not directly) dependent upon distance

so in a distance near infinite, the potential energy will nears zero

isn't, then, there, a point where the potential energy will be less than the energy of a possible interaction?

 

[nasu]

this is wrong:

potential energy is inversely (and not directly) dependent upon distance

so in a distance near infinite, the potential energy will nears zero

isn't, then, there, a point where the potential energy will be less than the energy of a possible interaction?

You should be more careful with your labels of "wrong".
The fact that the potential energy is zero at infinite is a matter of choosing the reference point but it is the usual choice . The fact that it decreases when the distance decreases is independent of the reference point. Then how can the zero value be a maximum? What values are less than zero?

 

[Dadface]

this is wrong:

It is not wrong. For attracting particles the greater the separation the greater the potential energy. You may be getting this mixed up with potential which by convention is taken to be zero at an infinite separation.

 

[mather]

It is not wrong. For attracting particles the greater the separation the greater the potential energy. You may be getting this mixed up with potential which by convention is taken to be zero at an infinite separation.

I am talking about electrostatic potential energy:

 

[nasu]

I am talking about electrostatic potential energy:

Everyone here does too, I suppose.
Not put q1=e and q2=-e.
What happens with W when r decreases?

 

[mather]

okay, but doesn't this prove you wrong?

 

[nasu]

I suppose you forgot your own words:

I am talking about electrostatic potential energy:

Your plot does not show that.

 

[mather]

I suppose you forgot your own words:



Your plot does not show that.

you mean that dissociation energy has nothing to do with electrostatical potential energy?

 

[nasu]

you mean that dissociation energy has nothing to do with electrostatical potential energy?

"has nothing to do" is a little too vague.
Let's put it this way: the Morse potential is not the electrostatic potential mentioned in your previous post. It contains a repulsive term which becomes very large at close approach. This term is not part of the electrostatic potential energy.
The distinction between the attractive, electrostatic, term and the repulsive terms is easier to see if you look at another common potential function, the Lenard-Jones potential.

However the energy at large distance (infinite) is higher than the energy in the bound state (minimum of the potential).
What was actually the problem?