Question

Why electron doesn't exist inside nucleus

Answer 1

Cause then chemistry would be boring, lol. And they probably wouldn't call it an electron then...

Answer 2

@SapphireMoon

😆

Answer 3

@IrishBoy123 Well, there isn't really another answer... idk... lol XD

Answer 4

the question really is weirdly stated. It's not as if electron can't get to the nucleus either. It's the basis for Rutherford experiment.

Plus some radioactive decays depends on the electron being there. For example beta decay for heavy elements is usually done via electron capture when a nucleus captures an orbiting electron and emits a neutrino

Answer 5

@SapphireMoon

i don't disagree!!!

Answer 6

Wouldn't the atom become unstable if the protons, neutrons, electrons all were inside the nucleus standing still

Answer 7

I guess that depends on what you imagine by "standing still". If the electron was standing still, you wouldn't know where it is. Heisenberg's uncertainty principle makes sure of that.

Pauli's exclusion principle states that there can't be two fermions occupying the same state. Notice that state, not place, to boot - protons are baryons.
As far as I'm aware of there is no law prohibiting electrons reaching the nuclei.

Even the wiki does not hide this fact:
" by considering the analogous case of standing waves on a circular drum.[26] ....then it will be seen that the many modes of the vibrating disk form patterns that trace the various shapes of atomic orbitals."
and if you pay close attention to the animated drum membranes you will see that in fact for s orbitals the highest probabilities of finding an electron is in the center of the drum membrane, where, in this analogy, the nucleus is located.
https://en.wikipedia.org/wiki/Atomic_orbital#Types_of_orbitals and https://en.wikipedia.org/wiki/Atomic_orbital#Orbitals_table

The question is badly worded and ill stated because OP probably isn't a college graduate, does not understand what he's actually looking at and is probably still thinking about particles as balls. To him all of this might sound a bit magicky and new-agey and just plain bullpellet. The question is bad because it's obviously intended to elicit a certain response the prof./teacher envisioned in the class, then mentioned it, and is now confident they remembered it. If you ask me OP should just probably copy whatever answer his classmates give.

As far as the actual answer goes:
The only thing you can actually say in reality about particles are their probabilities of being somewhere. And the probabilities for electrons to occupy the exact same spot as a proton or a neutron in the nucleus is not all that great but still, however, it does exist and you can probably even calculate it with just basic knowledge in QM. So if there's a chance for the electron to get in the nucleus and there's just about uncountable many atoms in the universe the chances are that this has happened/is happening often, why doesn't electron capture, big explosions and whatever popular tv has you imagining happens as often too?

Take electron capture for example. For it to work and for the proton to "collide" with the electron, the electron has to be close enough to be in the reach of the weak force which acts on ranges of something like 10^(-18)meters (~0.1% of proton "diameter"). Then to boot you're missing a lot of energy for the "collision" to happen. So, proton converts to a neutron. Mass difference tells us that we need about 1.3MeV additional energy (extra to the mass of proton) to make it happen. electron can give about 0.5MeV from its mass and the energy of the first orbital is in eV so not even worth accounting for. We're missing 0.8MeV which isn't a little in terms of subatomical particles (it's about 1.6x10^(-13) Joules which is laughably small for our scale, to put it in perspective 1 joule is about 0.2 calories, **minimal** caloric diets consist of about a 1000 calories a day). So even if it happens often, that electrons get inside nucleus, it's not like everytime there has to be some cataclysmic end-of-the-world reaction like they portray in the sequel of Da Vinci's Code. Chances are that the conditions aren't met and that the reaction is impossible. And even if on some **freak** occurrence it does happen, how would you even be able to tell? The energies are so small for our scales it's laughable.
Also, can you notice how many quotes I used in this paragraph to point I don't really imply what the word implies? That's because these everyday concepts look different on these scales and don't happen as if you were dealing with little colored balls or whatever helping tools are used these days.

To boot - representing electron as negatively charged particle and proton as its opposite - positively charged particle comes into play here. First of all electron and proton aren't even the same thing. One is a elementary particle (that is to say, we can't split it into any smaller particles) and the other is a composite particles consisting of three quarks (2 up and a down quark) and isn't even in the same particle family.

So having two things just in the same place is childs play when it comes to QM "weirdness". You can even have two electrons in the same place as long as their states are different, particles can tunnel through barriers and appear on the other side, bosons can occupy same *states* and this can happen even for large systems etc...
It's not intuitive why this can happen, but if you don't think of particles as "things" then it stops being that weird. When you look at two waves on a pond/lake/sea, is it weird to see them cross each others path as if they're invisible to each other? You get a constructive/destructive interference on the surface but in the background they're just moving along as if everything's normal.

Answer 8

Nice explaining, @ljetibo. (Except that little bit where you insult the OP. O.O Most of us aren't college or even high school graduates, I don't think.)

Answer 9

With all the risks of seeming to be combatant (which I'm not) I fail to see how pointing out the level of education in that context can be taken as an insult. Saying someone isn't a graduate student doesn't mean you're calling him/her stupid.

At best that part can be taken as an insult to the prof. whose wording, intention or lack of knowledge fails to paint a realistic picture of what particles are and how they behave, leading the op and other students of the prof./teach. into misconceptions.

It was mostly meant, however, as an expression of my own frustrations when facing these kinds of questions at not a sufficient level of in depth knowledge that is required to answer the question in fully. The problem is that then both I and my answer seem like mumbo-jumbo and senseless and the question itself doesn't further any kind of understanding of physics for the students. At best these questions can then be answered as: "because the electron spins around so there's centrifugal force pushing it outwards while the lorentz force of electrical attraction acts as the centripetal force." which is not how any of this works.
I run into these question often, worst example being when a highschooler had to make a poster explaining black holes that was then graded poorly because the explanations on it were based on popular knowledge from mainstream media and science populators and apparently "there was no actual information or definitions of what black holes are". When someone's lacking the ground knowledge you have to use to define the things you want to talk about makes the defining of the thing you need to talk about - impossible. It's not the students fault for this, why would it be, it's hard stuff with hard math.
Is it really that hard to think of a classical mechanics, electrodynamics and other phoenomena that would much easier and much much more accurately depict the atom?

Of course then again none of this has to actually be placed in a classroom, but the question is just so similar to the questions I run into when profs. don't think through or do the research.

Answer 10

@ljetibo I specifically meant the sentence where you say he "doesn't understand what he's looking at." I see how you and I might not perceive that as an insult (I apparently have little to no understanding of what is and is not offensive) but someone else might, I really wouldn't know, I guess. But I totally get what you're saying. Someone shouldn't have to understand the math to get the answers right, especially when they haven't learned calculus yet (which most people take in their senior year of high school if not in college).