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Can we "fill" an atom with alpha particles?

by Meson080
Tags: alpha, atom, particles
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DaleSpam
#19
Aug11-14, 12:04 PM
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Quote Quote by Meson080 View Post
Can you elaborate?

If the atom gets filled by alpha particles, for the layman like me, the space for the electron should decrease. Or else electron should have got different space, does the electron buys different land around nucleus?
Unfortunately, nature didn't ask for the opinions of laymen when she picked the rules, but don't feel too bad, she didn't ask for the opinions of experts either.

Look at these images of electron orbitals for hydrogen:
http://en.wikipedia.org/wiki/Hydroge...ctron_orbitals

The bright spots are regions where the electron is likely to be, and the dark spots are regions where the electron is unlikely to be. Note that, for the s orbitals, the brightest spot is right in the middle, on top of the nucleus. In other words, the s electron is more likely to be in the nucleus than in any other spot of similar volume.

Weird, but that is how it is. Increasing the number of nucleons doesn't change this at all, although increasing the number of electrons changes the wavefunctions quantitatively, but not qualitatively.
Drakkith
#20
Aug11-14, 01:02 PM
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Quote Quote by Meson080 View Post
What about dipping the atoms into the sea of alpha particles?
There is no such thing. Alpha particles are highly charged particles that are emitted by radioactive decay and immediately steal electrons from whatever material they happen to come to a stop in. You will not find a "sea" of alpha particles nor could you even make one.
Meson080
#21
Aug12-14, 11:37 AM
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Quote Quote by DaleSpam View Post
Unfortunately, nature didn't ask for the opinions of laymen when she picked the rules, but don't feel too bad, she didn't ask for the opinions of experts either.

Look at these images of electron orbitals for hydrogen:
http://en.wikipedia.org/wiki/Hydroge...ctron_orbitals

The bright spots are regions where the electron is likely to be, and the dark spots are regions where the electron is unlikely to be. Note that, for the s orbitals, the brightest spot is right in the middle, on top of the nucleus. In other words, the s electron is more likely to be in the nucleus than in any other spot of similar volume.

Weird, but that is how it is. Increasing the number of nucleons doesn't change this at all, although increasing the number of electrons changes the wavefunctions quantitatively, but not qualitatively.
How could the electrons have the probability of having the position at the place where there are already quarks? Did electron learn the magic of entering the body of quarks?
Meson080
#22
Aug12-14, 11:43 AM
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Quote Quote by Drakkith View Post
There is no such thing. Alpha particles are highly charged particles that are emitted by radioactive decay and immediately steal electrons from whatever material they happen to come to a stop in. You will not find a "sea" of alpha particles nor could you even make one.
Not even in "high security" condition?
Orodruin
#23
Aug12-14, 11:52 AM
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You seem to be working under the assumption that elementary particles are small balls that have a non-zero size. This is not the case in quantum mechanics (or classical particle theory either for that matter).
Drakkith
#24
Aug12-14, 12:12 PM
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Quote Quote by Meson080 View Post
How could the electrons have the probability of having the position at the place where there are already quarks? Did electron learn the magic of entering the body of quarks?
Elementary particles are considered to be "point like" in that they have no size. Of course, this is a very simplified version of the truth, which is far more complicated in quantum physics and depends on how you define the size of a particle, of which there is no single answer.

Quote Quote by Meson080 View Post
Not even in "high security" condition?
I don't know what this means.
DaleSpam
#25
Aug12-14, 12:41 PM
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Quote Quote by Meson080 View Post
Did electron learn the magic of entering the body of quarks?
Yes.

More explicitly, quarks don't have a definite location any more than the electrons, and even if they did the Pauli exclusion principle only applies to identical fermions and would therefore not prevent colocation of a quark and an electron.

You are thinking purely classically, your classical assumptions are simply wrong at the quantum level.
Meson080
#26
Aug13-14, 08:03 PM
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Quote Quote by Orodruin View Post
You seem to be working under the assumption that elementary particles are small balls that have a non-zero size. This is not the case in quantum mechanics (or classical particle theory either for that matter).
Did you mean that elementary particles have zero size?
Meson080
#27
Aug13-14, 08:07 PM
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Quote Quote by Drakkith View Post
I don't know what this means.
"High Security" condition = Sophisticated condition.
Meson080
#28
Aug13-14, 08:11 PM
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Quote Quote by Meson080 View Post
Did electron learn the magic of entering the body of quarks?
Quote Quote by DaleSpam View Post
Yes.
Interesting, I will be back with the words within hours.
Drakkith
#29
Aug13-14, 08:30 PM
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Quote Quote by Meson080 View Post
Did you mean that elementary particles have zero size?
Yes, but the concept of "size" is poorly defined at the quantum level due to the unique nature of quantum sized objects and the fact that they obey both wave and particle rules. I know there are a few threads around PF on the subject. I'd recommend searching for them.

Quote Quote by Meson080 View Post
"High Security" condition = Sophisticated condition.
I still don't understand what this means in the context of my earlier explanation.
Meson080
#30
Aug14-14, 09:19 PM
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Quote Quote by Meson080 View Post
How could the electrons have the probability of having the position at the place where there are already quarks? Did electron learn the magic of entering the body of quarks?
Quote Quote by DaleSpam View Post
Yes.
Quote Quote by Feynman
You know, of course, that atoms are made with positive protons in the nucleus and with electrons outside. You may ask: "If this electrical force is so terrific, why don't the protons and electrons just get on top of each other? If they want to be in an intimate mixture, why isn't it still more intimate?" The answer has to do with quantum effects. If we try to confine our electrons in a region that is very close to the protons, then according to the uncertainty principle they must have some mean square momentum which is larger the more we try to confine them. It is this motion, require by the laws of quantum mechanics, that keeps the electrical attraction from bringing the charges any closer.
I am really perplexed, Feynman says electrons can't get on top of protons, Dalespam says electrons have learnt the magic of entering the body of protons (which consists of quarks). Whom shall I believe?

[The Feynman's quote has been extracted from Feynman's Lectures on Physics-Vol ll]
Meson080
#31
Aug14-14, 09:36 PM
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Quote Quote by Meson080 View Post
Did you mean that elementary particles have zero size?
Quote Quote by Drakkith View Post
Yes, but the concept of "size" is poorly defined at the quantum level due to the unique nature of quantum sized objects and the fact that they obey both wave and particle rules.
I don't think we should think/talk about anything which is defined poorly. Even it is not sensible to say zero or non-zero "size".
Meson080
#32
Aug14-14, 09:50 PM
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Quote Quote by Meson080 View Post
What about dipping the atoms into the sea of alpha particles?
Quote Quote by Drakkith View Post
There is no such thing. Alpha particles are highly charged particles that are emitted by radioactive decay and immediately steal electrons from whatever material they happen to come to a stop in. You will not find a "sea" of alpha particles nor could you even make one.
Quote Quote by Meson080 View Post
Not even in "high security" condition?
Quote Quote by Drakkith View Post
I don't know what this means.
"High Security" condition = Sophisticated condition = ICU condition = Condition of forming the sea of alpha particles without bringing any conflicts (e.g the conflicts you mentioned).
DaleSpam
#33
Aug14-14, 09:51 PM
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Quote Quote by Meson080 View Post
I am really perplexed, Feynman says electrons can't get on top of protons, Dalespam says electrons have learnt the magic of entering the body of protons (which consists of quarks). Whom shall I believe?

[The Feynman's quote has been extracted from Feynman's Lectures on Physics-Vol ll]
We are both correct. Feynman is answering a different question than what you are asking, so you shouldn't be surprised that the answers are different.

In any case, this whole line of discussion was an attempt to avoid the uncertainty principle, which is the basis of Feynman's comment. So either way, even if you think there is some conflict in our two statements, you still wind up with the uncertainty principle.
Drakkith
#34
Aug14-14, 11:22 PM
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Quote Quote by Meson080 View Post
"High Security" condition = Sophisticated condition = ICU condition = Condition of forming the sea of alpha particles without bringing any conflicts (e.g the conflicts you mentioned).
I will not answer any "what if" questions that require us to handwave the laws of physics aside. It's pointless and will most likely lead to further confusion.
DaleSpam
#35
Aug15-14, 09:07 AM
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Quote Quote by DaleSpam View Post
Feynman is answering a different question than what you are asking, so you shouldn't be surprised that the answers are different.
To be a little more explicit, Feynman's comments were answering the question "why is the electron not constrained to be inside the proton?" The answer is that the uncertainty principle for such a tightly constrained position for the electron would have a very high mean momentum and therefore a high mean KE.

My comments were answering the question "why is the electron not constrained to be outside of the proton?" The answer is that the Pauli exclusion principle only constrains identical fermions, so it does not constrain an electron and a proton.

The electron is not constrained to be inside the proton (Feynman) and it is also not constrained to be outside the proton (me). The two comments are perfectly compatible.
Meson080
#36
Aug16-14, 08:47 PM
P: 100
I will read the necessary things of QM and then we can continue our discussion. I felt that the discussion would go long (without quality) without my better understanding. I will come back latter. Thank you for all your support.

Others can continue the discussion, if liked.


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