Electrons, Protons, neutrons, the nucleus, and lots of questions.

[Spork Schivago]

Hi!

When I took chemistry back in High School, I was taught that atoms have a nucleus made up of protons and neutrons, with protons having a positive charge, and neutrons having no charge, except for in the simple hydrogen atom, which has no neutrons. The protons had a mass equal to the electrons mass in the atoms valence shells, just opposite charge.

Now it seems this might not be so true. From what I've been reading, the "valence shells" are actually a cloud. Different levels are just like clouds here on earth, either further or closer to the nucleus. If this is true, am I correct in thinking that electrons are more like a wave moving through the clouds?

If you had a hypothetical net and you put in the first valence shell, the one closest to the nucleus of the atom, the innermost one, and let's say it covered 50% of that cloud, that wouldn't mean you'd get have the electrons, would it? You'd have a 50% chance of getting some electrons, you might get none, etc? Is that right?

Having a hard time learning about it because there's soooo much conflicting information out there on the net. Some show the old picture I learned in high school, some say an electron is only hypothetical and doesn't actually exist, Wikipedia (listing sources) says, All the particles of the Standard Model have been experimentally observed, recently including the Higgs boson.

Seeing how the electron belongs to the leptons group, which is part of the standard model, it would seem the electron is now no-longer hypothetical, but absolutely exists, along with all the other particles on the Standard Model....

https://en.wikipedia.org/wiki/List_o...tary_particles

Could someone with more recent knowledge who studies in the field, or keeps up with the latest news help me out here?

Is my hypothesis right about the electron cloud and the electrons being more like waves moving through that cloud, rather than particles orbiting the nucleus correct?

Thanks!

[eccerr0r]

Re: Electrons, Protons, neutrons, the nucleus, and lots of questions.

It's been many years since chemistry, then again a lot of this is physics too. I only read and not a chemist/physicist.

Anyway, proton mass is about equal to neutron mass, but both far exceed electron mass (I've always heard electrons had mass, though extremely small. When was it taught they didn't have mass?).
Proton charge is equal but opposite to electron charge.
Electrons surround the nucleus in discrete 'shell' 'levels' and depending on how many there are at that level, there are discrete (quantum physics!) levels that they can exist in. Yes they sort of behave like waves, they're there or they're not there and nowhere in between.

A lot of this has changed over the years because more information was found, but the old information is still out there - and the information is not exactly useless, just wrong (get your mind around that?). It becomes really complicated due to quantum effects.

Even Einstein was baffled by quantum theory, so it indeed is confusing and complicated.

[Curious.George]

Re: Electrons, Protons, neutrons, the nucleus, and lots of questions.

Now it seems this might not be so true. From what I've been reading, the "valence shells" are actually a cloud. Different levels are just like clouds here on earth, either further or closer to the nucleus.

Actually, each "orbit" consists of a set of such "clouds" -- called "subshells". The orbit number determines the number of subshells that it can support.

The smallest subshell is 's' and is present in all orbits/shells. It can hold 2 electrons. So, once you slip past natural He, the "1s" (orbit 1, subshell s) subshell is full and the next electron has to move to a higher energy level subshell. This would nominally be the 'p' subshell -- which can hold 6 electrons.

Each subshell has a distinct shape (as if a 3D surface).

[I'm sure you can probably find a graphic illustrating the shapes of these subshells with google]

But, as I mentioned, the closer orbits support fewer subshells. So, 1 just supports 's' while 2 supports s and p. Moving to orbit 3 allows support for the 'd' subshell which can hold 10. The 4th orbit adds support for the 'f' subshell holding 14, etc.

The order in which subshells (and, thus, orbits) "fill" tries to minimize the energy stored in the atom. This often causes higher subshells in orbit N to be filled AFTER lower subshells in orbit N+1! E.g., you would fill:
1s, 2s, 2p, 3s, 3p (so far, this seems to be orderly!), 4s (NOT 3d!!), 3d (i.e., after there have been 2 electrons stuffed into the 4th orbit "above", 4p, 5s (again, note how 4d got skipped over, temporarily), 4d, 5p, 6s ...

Knowing the fill order lets you predict the stability/reactivity of a particular atom because you can determine which shells/subshells are "sated", or not.

But, the classical model of electrons being "planets" orbiting a nucleus is too naive. In reality, they exist in surfaces surrounding the nucleus. And, the electron is never really "anywhere" -- or, equivalently, EVERYWHERE! (it's hiding with Schrödinger's cat!)

[Spork Schivago]

Re: Electrons, Protons, neutrons, the nucleus, and lots of questions.

It's been many years since chemistry, then again a lot of this is physics too. I only read and not a chemist/physicist.

Anyway, proton mass is about equal to neutron mass, but both far exceed electron mass (I've always heard electrons had mass, though extremely small. When was it taught they didn't have mass?).
Proton charge is equal but opposite to electron charge.
Electrons surround the nucleus in discrete 'shell' 'levels' and depending on how many there are at that level, there are discrete (quantum physics!) levels that they can exist in. Yes they sort of behave like waves, they're there or they're not there and nowhere in between.

A lot of this has changed over the years because more information was found, but the old information is still out there - and the information is not exactly useless, just wrong (get your mind around that?). It becomes really complicated due to quantum effects.

Even Einstein was baffled by quantum theory, so it indeed is confusing and complicated.

Yes, my problem is trying to sift through the old, incorrect information, and the new found data. I think when they were looking for the Higgs Boson, a lot changed. But also, I saw some video (a few of the same) where the news person claims it's a video of an actual electron being recorded in motion, slowed down very, very, very much so we can view it. But I guess that was incorrect. The video is (incorrectly I believe) entitled, "Scientists in Sweden film moving electron for the first time"

But someone says that's not a video of an actual electron, but some ion reaction, and the news people just misinterpreted the original scientific article. So that definitely adds to the confusion a bit.

When you say, "Anyway, proton mass is about equal to neutron mass, but both far exceed electron mass (I've always heard electrons had mass, though extremely small. When was it taught they didn't have mass?)."

I was taught that the proton and neutron mass equal the electron mass, exactly, except for in hydrogen particles, which don't have a neutron, where they only have a proton. So I need clarification on that as well. Does the electron not way the exact same as the proton + neutron (or just proton in Hydrogen particles)?

[Spork Schivago]

Re: Electrons, Protons, neutrons, the nucleus, and lots of questions.

Actually, each "orbit" consists of a set of such "clouds" -- called "subshells". The orbit number determines the number of subshells that it can support.

The smallest subshell is 's' and is present in all orbits/shells. It can hold 2 electrons. So, once you slip past natural He, the "1s" (orbit 1, subshell s) subshell is full and the next electron has to move to a higher energy level subshell. This would nominally be the 'p' subshell -- which can hold 6 electrons.

Each subshell has a distinct shape (as if a 3D surface).

[I'm sure you can probably find a graphic illustrating the shapes of these subshells with google]

But, as I mentioned, the closer orbits support fewer subshells. So, 1 just supports 's' while 2 supports s and p. Moving to orbit 3 allows support for the 'd' subshell which can hold 10. The 4th orbit adds support for the 'f' subshell holding 14, etc.

The order in which subshells (and, thus, orbits) "fill" tries to minimize the energy stored in the atom. This often causes higher subshells in orbit N to be filled AFTER lower subshells in orbit N+1! E.g., you would fill:
1s, 2s, 2p, 3s, 3p (so far, this seems to be orderly!), 4s (NOT 3d!!), 3d (i.e., after there have been 2 electrons stuffed into the 4th orbit "above", 4p, 5s (again, note how 4d got skipped over, temporarily), 4d, 5p, 6s ...

Knowing the fill order lets you predict the stability/reactivity of a particular atom because you can determine which shells/subshells are "sated", or not.

This is how I was taught in Chemistry, minus the cloud part. And google is half the problem here. Some show the model I was shown in high school chemistry, some (like this: http://faculty.wcas.northwestern.edu...Plate%201.html )

I was always taught the "What an Atom Isn't" picture, which now seems to be considered wrong.

I'm trying to better understand the new, I guess not really hypothesis, because it's been physically observed while searching for the Higgs Boson, so I guess the way it really looks and works now.

But, the classical model of electrons being "planets" orbiting a nucleus is too naive. In reality, they exist in surfaces surrounding the nucleus. And, the electron is never really "anywhere" -- or, equivalently, EVERYWHERE! (it's hiding with Schrödinger's cat!)

Now it seems electrons are not particles, they act like waves most of the time, but carry discrete mass and momentum as though they are particles.

I understand an electron cannot move up a level to a higher valence shell without input of energy from the outside, but it can move downwards. I know that the inner most valence shells get filled first, I understand the number of electrons they hold still hasn't changed (1st "orbital" valence shell holds up to two electrons, no more, etc, etc).

This whole cloud thing and what an electron actually looks like is confusing me though. It's not what I was taught and I'm trying to wrap my head around it now. The orbital cloud or whatever we call it can actually compress and expand I guess?

Does this article seem scientifically accurate? http://faculty.wcas.northwestern.edu.../pressure.html

[eccerr0r]

Re: Electrons, Protons, neutrons, the nucleus, and lots of questions.

Electrons don't weigh the same as other subatomic particles. They're leptons and not baryons.

Through experimentation they've found that the mass of an atom is virtually entirely at the nucleus of the atom - all the protons and neutrons. Experimentally, they've found that charged atoms - ones that lack electrons - weigh the same as uncharged atoms. Plus they've shot electron beams at targets and found that the electrostatic force exerted far exceeds the force exerted by mass, to conclude electrons have near negligible mass.

I'm not sure what you're saying here: they do know that isotopes of atoms exist where neutron count differs but electrons do not (if not charged). If the sum of all the proton and neutron mass is equal to electron mass, then all isotopes must weigh the same as they all have the same number of electrons (and protons) - which is not true.

The common hydrogen atom has one proton and one electron. If proton mass equals electron mass, then you have 2 mass producing particles. There is an isotope of hydrogen, called deuterium, which has a proton and a neutron, and the electron.

If proton+neutron mass = electron mass, then the atomic mass is still 2. However they have found that the deuterium atom was measured to be significantly heavier than the hydrogen atom, so this can't be correct.

If proton = neutron = electron mass, then the atomic mass would be 3. This is 50% heavier than the hydrogen atom, but they found that the deuterium atom to be almost twice as heavy - 100%, so this can't be correct either.

Now how did they figure this out? That's the trick. Deuterium mostly has to be extracted from water and once they had the theory of the neutron in place, they were able to separate the heavy, deuterium-laden water out of regular water, and got the deuterium from there. Then they can do experiments from that from electrolysis.

[Spork Schivago]

Re: Electrons, Protons, neutrons, the nucleus, and lots of questions.

Electrons don't weigh the same as other subatomic particles. They're leptons and not baryons.

Through experimentation they've found that the mass of an atom is virtually entirely at the nucleus of the atom - all the protons and neutrons. Experimentally, they've found that charged atoms - ones that lack electrons - weigh the same as uncharged atoms. Plus they've shot electron beams at targets and found that the electrostatic force exerted far exceeds the force exerted by mass, to conclude electrons have near negligible mass.

Thank you!

I'm not sure what you're saying here: they do know that isotopes of atoms exist where neutron count differs but electrons do not (if not charged). If the sum of all the proton and neutron mass is equal to electron mass, then all isotopes must weigh the same as they all have the same number of electrons (and protons) - which is not true.

This is why I'm asking. The stuff I was taught in high school chemistry is obviously wrong. But perhaps at the time, is was a commonly held hypothesis that no longer holds true? Also, I'm sure things where simplified in high school chemistry, for the simple fact that it wasn't a quantum mechanics class. We never got into any quantum theory.

The common hydrogen atom has one proton and one electron. If proton mass equals electron mass, then you have 2 mass producing particles. There is an isotope of hydrogen, called deuterium, which has a proton and a neutron, and the electron.

If proton+neutron mass = electron mass, then the atomic mass is still 2. However they have found that the deuterium atom was measured to be significantly heavier than the hydrogen atom, so this can't be correct.

If proton = neutron = electron mass, then the atomic mass would be 3. This is 50% heavier than the hydrogen atom, but they found that the deuterium atom to be almost twice as heavy - 100%, so this can't be correct either.

Now how did they figure this out? That's the trick. Deuterium mostly has to be extracted from water and once they had the theory of the neutron in place, they were able to separate the heavy, deuterium-laden water out of regular water, and got the deuterium from there. Then they can do experiments from that from electrolysis.

Okay, I was not saying proton = neutron = electron mass. I was taught proton + neutron = electron mass, which is wrong, right? But your statement here:

 If proton mass equals electron mass, then you have 2 mass producing particles.

when you say then you have 2 mass producing particles....are you saying that an electron is actually a particle? But it acts like a wave, right? I think this might be called wave–particle duality and I'm having a hard time understanding the wave-particle duality.

Finally, when an electron moves from one orbit to another, they say it's never in between an orbit. It's either in one or another. So how does it get there? I don't see how something can just magically be in one location and then appear in another. Is it just happening so fast we don't see the jump? Or does it move outside space and time?

**EDIT: Or is it behaving like a wave, it gets hit with a photon, absorbs the energy, and it's wavelength changes, putting it at a higher orbital than before?

[eccerr0r]

Re: Electrons, Protons, neutrons, the nucleus, and lots of questions.

Strange. The mass of protons, neutrons, and electrons have been well understood for at least the past half century and more, perhaps it was a mere confusion between proton charge and electron charge - these are equal but opposite, and neutrons do not contribute to the electrical charge. In this case proton+neutron charge is equal (and opposite) to electron charge, which would be true in an un-ionized (not union-ized...) atom.

Anyway, for simplicity, electrons can be modeled as a particle though due to quantum effects its behavior is weird around atoms and hence the weirdness that it can't be between shells.

When it's outside an atom, like in an electron guns in CRTs, they don't orbit anything. Experimenting with that electron beam, it has been discovered they behave clearly particle-like.

And yes it's basically magically showing up in the other orbital due to quantum mechanics. On the other hand, it's photons that have wave-particle duality and are even weirder.

Quantum mechanics is weird, try explaining quantum entanglement ("voodoo") hence there are a lot of things that simply can't be explained but appear to be true...

[Spork Schivago]

Re: Electrons, Protons, neutrons, the nucleus, and lots of questions.

Strange. The mass of protons, neutrons, and electrons have been well understood for at least the past half century and more, perhaps it was a mere confusion between proton charge and electron charge - these are equal but opposite, and neutrons do not contribute to the electrical charge. In this case proton+neutron charge is equal (and opposite) to electron charge, which would be true in an un-ionized (not union-ized...) atom.

Anyway, for simplicity, electrons can be modeled as a particle though due to quantum effects its behavior is weird around atoms and hence the weirdness that it can't be between shells.

When it's outside an atom, like in an electron guns in CRTs, they don't orbit anything. Experimenting with that electron beam, it has been discovered they behave clearly particle-like.

And yes it's basically magically showing up in the other orbital due to quantum mechanics. On the other hand, it's photons that have wave-particle duality and are even weirder.

Quantum mechanics is weird, try explaining quantum entanglement ("voodoo") hence there are a lot of things that simply can't be explained but appear to be true...

I also have memory issues. Sometimes, memories collide and combine, separate memories, and form one. So maybe in reality, she was teaching us how to calculate the atomic weight and in my broken memory, I remember her telling us that the weight of the electron equals the weight of the proton + neutron (except for in Hydrogen, which has only the proton).

Quantum Entanglement...that was something I thought I understood pretty well. Scientists did some recent experiments not too long ago on that and figure the atoms must be sending messages of one sort or another to each other. They have to be communicating somehow, right? So they moved two quantum entangled atoms about 500 miles away from each other (I believe) and tried to measure how fast these messages were being sent. It was something amazing, like 15,000x the speed of light. The concluded that the messages must be being sent outside of space and time.

Now, granted, the results could easily be debated, I'm certain. For example, how easily could scientists, with current technology, measure something so fast? So I like the idea, but I don't take it as strong scientific supporting evidence yet. I think more tests need to be done.

When it's outside an atom, like in an electron guns in CRTs, they don't orbit anything. Experimenting with that electron beam, it has been discovered they behave clearly particle-like.

This happens in white-dwarfs as well, correct? The electrons break free from their orbit around the atom and behave just like particles. The exclusion rule still applies. And not too long ago, it was thought you could throw an infinite amount of energy into a white-dwarf and it'd be absorbed. That there was no limit to how much energy those electrons would absorb. I think it was around the 1930's a scientific came up the hypothesis that there was a limit, and it was roughly 1.4x the size of our sun. If a white-dwarf was any larger, it would actually collapse upon itself. At the time, many people disregarded this. The guy that helped Einstein with the sun-light experiment said it was nonsense and that pretty much described the scientist. He ended up leaving his job at (Cambridge I think?) and going to Chicago University and spent the rest of his days teaching there.

But over the years, astronomers found many white dwarfs and none of them where larger than 1.4x the size the sun. So people started looking into hypothesis and he was in fact correct.


So where's a good free site to learn quantum mechanics and should I take basic physics courses first? Would Khan-Academy be a good place?

[Spork Schivago]

Re: Electrons, Protons, neutrons, the nucleus, and lots of questions.

When I say quantum mechanics, just so we're clear, I want to find a good free resource to learn quantum electrodynamics. Maybe the MIT OpenCourseware is a good place to start:

https://ocw.mit.edu/courses/physics/

I used them before, and I thought some of their IT courses where very well laid out, and even though I majored in Computer Science, and then Chem Tech, and finally Computer Repair and Networking, their basic class on Python taught me stuff that I didn't learn up at my local community college. Stuff that I thought was important and should have been taught up there.

I think I'll start some of their physics classes and see where things go. Maybe it'll answer a lot of my questions.