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Electron Affinity

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How does an electron add up(enters) in the valance shell of an atom? Why is energy released when an electron adds up in the valance shell of an isolated atom.
 

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8 minutes ago, XVV said:
How does an electron add up(enters) in the valance shell of an atom? Why is energy released when an electron adds up in the valance shell of an isolated atom.
 

To understand electron affinity properly you need to understand three terms.

Electron affinity
Electronegativity
Ionisation energy

Before I reply about electon affinity how about you put some more meat on the bones of your question to connect it to your opening post?

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Because of quantum mechanics, electrons tend to be in "valleys" of their potential energy well called molecular orbitals. For an isolated atom those would be atomic orbitals. In an isolated atom, the electron is not always better in the valence shell. Depends on the temperature too. On the other hand, rarely are atoms completely isolated, except maybe in a Penning trap.

Somebody will correct me if I'm wrong, but I don't think the electron in the valence shell of a Lithium atom would be very "happy" being there.

I concur with Studiot that there's something missing in your premises. Maybe you don't want to say an "isolated" atom. We'll work through it, I'm sure. Clearly something's bothering you.

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43 minutes ago, joigus said:

Because of quantum mechanics, electrons tend to be in "valleys" of their potential energy well called molecular orbitals. For an isolated atom those would be atomic orbitals.

 

@XVV, are you sure you understand this ie the difference between atoms and molecules?

I asked because I wanted to know where you think the electron comes from when it

1 hour ago, XVV said:

How does an electron add up(enters) in the valance shell of an atom?

 

So tell us more.

The more you put into the discussion,  the more you will get out of it.

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17 minutes ago, studiot said:

 

@XVV, are you sure you understand this ie the difference between atoms and molecules?

I asked because I wanted to know where you think the electron comes from when it

 

So tell us more.

The more you put into the discussion,  the more you will get out of it.

Yes

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Posted (edited)

On the example of Hydrogen-1 atom: free proton, and free electron have higher mass-energy than bound together proton and electron.

Similarly free nucleus (multiple protons and eventually neutrons bound together) and many free electrons have higher mass-energy than when they are bound together.

If they join together, energy is released. Usually in the form of multiple lower energy photons.

This process can be reversed. When energy is delivered to atom, molecule, electron is ejected. Usually energy is delivered by particles in the form of kinetic energy. Photons with enough energy, electrons with enough kinetic energy, or other particles or molecules with enough kinetic energy.

It is what scientists call ionization energy. https://en.wikipedia.org/wiki/Ionization_energy

Different particles, different elements, different isotopes, have different ionization energies.

e.g. if you have Helium-4 element with 2 electrons it is electric neutral atom. After 1st ionization it changes to positively charged He+ nucleus and free e-. After 2nd ionization it changes to He2+ and two free electrons e-. He2+ is also called alpha particle. https://en.wikipedia.org/wiki/Alpha_particle

2nd and further ionizations require significantly more and more energy. Outermost (valence) electrons are the easiest to be ejected. Innermost (the closest to nucleus) are the hardest to be ejected.

The example gave by joigus, Lithium has small energy of 1st ionization.

As you can read in this table it requires 5.39172 eV energy. For instance ionization energy of Hydrogen is 13.6 eV. Two and half more energy needed to eject electron.

https://en.wikipedia.org/wiki/Ionization_energies_of_the_elements_(data_page)

If Lithium has contact with element (let's call it "X") which has not fully filled orbitals, Lithium valence electron is intercepted, and Li+ positive ion and X- negative ions are created. They are still bound by electrostatic forces, ionic bonding https://en.wikipedia.org/wiki/Ionic_bonding

 

Similarly, stable isotopes made of multiple nucleons (i.e. protons and neutrons), https://en.wikipedia.org/wiki/Nucleon , bound together are at lower energy state than when they are free.

Energy needed to disintegrate their nuclei is called nuclear binding energy https://en.wikipedia.org/wiki/Nuclear_binding_energy

Unstable isotopes have enough mass-energy by themselves, therefore they decay to lower energy state isotopes and various 3rd party particles, in various radioactive decay paths https://en.wikipedia.org/wiki/Decay_chain

 

I hope so this will help a bit for a while. Read carefully the all articles in links that I gave.

 

Edited by Sensei

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Posted (edited)
8 minutes ago, Sensei said:

On the example of Hydrogen-1 atom: free proton, and free electron have higher mass-energy than bound together proton and electron.

Similarly free nucleus (multiple protons and eventually neutrons bound together) and many free electrons have higher mass-energy than when they are bound together.

If they join together, energy is released. Usually in the form of multiple lower energy photons.

This process can be reversed. When energy is delivered to atom, molecule, electron is ejected. Usually energy is delivered by particles in the form of kinetic energy. Photons with enough energy, electrons with enough kinetic energy, or other particles or molecules with enough kinetic energy.

It is what scientists call ionization energy. https://en.wikipedia.org/wiki/Ionization_energy

Different particles, different elements, different isotopes, have different ionization energies.

e.g. if you have Helium-4 element with 2 electrons it is electric neutral atom. After 1st ionization it changes to positively charged He+ nucleus and free e-. After 2nd ionization it changes to He2+ and two free electrons e-. He2+ is also called alpha particle. https://en.wikipedia.org/wiki/Alpha_particle

2nd and further ionizations require significantly more and more energy. Outermost (valence) electrons are the easiest to be ejected. Innermost are the hardest to be ejected.

The example gave by joigus, Lithium has small energy of 1st ionization.

As you can read in this table it requires 5.39172 eV energy. For instance ionization energy of Hydrogen is 13.6 eV. Two and half more energy needed to eject electron.

https://en.wikipedia.org/wiki/Ionization_energies_of_the_elements_(data_page)

If Lithium has contact with element (let's call it "X") which has not fully filled orbitals, Lithium valence electron is intercepted, and Li+ positive ion and X- negative ions are created. They are still bound by electrostatic forces, ionic bonding https://en.wikipedia.org/wiki/Ionic_bonding

 

Similarly, stable isotopes made of multiple nucleons (i.e. protons and neutrons), https://en.wikipedia.org/wiki/Nucleon , bound together are at lower energy state than when they are free.

Energy needed to disintegrate their nuclei is called nuclear binding energy https://en.wikipedia.org/wiki/Nuclear_binding_energy

Unstable isotopes have enough mass-energy by themselves, therefore they decay to lower energy state isotopes and various 3rd party particles, in various radioactive decay paths https://en.wikipedia.org/wiki/Decay_chain

 

I hope so this will help a bit for a while. Read carefully the all articles in links that I gave.

 

I am asking of Electron Affinity, not ionization energy. 

How does an electron add up(enters) in the valance shell of an atom? Why is energy released when an electron adds up in the valance shell of an isolated atom.
This is what I am asking. Can someone please answer accordingly?
Edited by XVV

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41 minutes ago, XVV said:

Yes

 

Perhaps you should model your answers for length on Sensei's.

 

An atom is electrically neutral.

An ion is an atom with an electric charge.

This charge can be positive (positive ion) or negative (negative ion).

The three terms I referred to are all measures of electron attracting power.

Because we have three different things (positive ions, neutral atoms and negative ions) we need three different measures.

So

The ionisation energy is the energy required to remove an electron from a neutral atom. (this is always positive since it always requires energy to remove an electron)

The  electron affinity is the energy required to add an electron to a neutral atom. (this may be positive or negative since some atoms require energy and some yield energy when your reove an electron).

The electronegativity is a sort of average of the two figures.

 

 

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3 minutes ago, studiot said:

 

Perhaps you should model your answers for length on Sensei's.

 

An atom is electrically neutral.

An ion is an atom with an electric charge.

This charge can be positive (positive ion) or negative (negative ion).

The three terms I referred to are all measures of electron attracting power.

Because we have three different things (positive ions, neutral atoms and negative ions) we need three different measures.

So

The ionisation energy is the energy required to remove an electron from a neutral atom. (this is always positive since it always requires energy to remove an electron)

The  electron affinity is the energy required to add an electron to a neutral atom. (this may be positive or negative since some atoms require energy and some yield energy when your reove an electron).

The electronegativity is a sort of average of the two figures.

 

 

I know all this. But no one is answering my question accordingly.

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A bound state is almost always a lower energy state than the 'free' state.
( one exception, off the top of my head, are nucleon states for Iron, 26, or higher )
So when an electron is 'captured' into a bound state, the excess energy is released as EMR.

If the electron affinity is not there, because the valence shell is adequately populated, you need to supply energy to bind an electron.

Not sure exactly what your question is, so difficult to answer accordingly.

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Posted (edited)
8 minutes ago, MigL said:

A bound state is almost always a lower energy state than the 'free' state.
( one exception, off the top of my head, are nucleon states for Iron, 26, or higher )
So when an electron is 'captured' into a bound state, the excess energy is released as EMR.

If the electron affinity is not there, because the valence shell is adequately populated, you need to supply energy to bind an electron.

Not sure exactly what your question is, so difficult to answer accordingly.

No you are wrong. Only you are not understanding the question. I have asked this question on 3 more websites. They understood the question and nicely explained the answer instead of just finding faults in the questions if they can't figure out its answer.

Edited by XVV

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If you already have an answer to your question , why do you keep reposting on different sites ?
And if you know that I'm wrong, or misinterpreted your question, why are you still going on about it, drama queen ?

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Posted (edited)
8 minutes ago, MigL said:

If you already have an answer to your question , why do you keep reposting on different sites ?
And if you know that I'm wrong, or misinterpreted your question, why are you still going on about it, drama queen ?

First of all, I am not a drama queen. I didn't repost the question on all websites simultaneously. I just posted this question on 3 websites in a span of a week bcz of not getting answers and then I posted on this website. Luckily, I suddenly got understandable answers from all those websites just today. Anyway I just now know that no one can give answers on this website. your reply proves that I was right about saying that there are more stupid insults instead of good answers.

Edited by XVV

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2 hours ago, XVV said:
How does an electron add up(enters) in the valance shell of an atom? Why is energy released when an electron adds up in the valance shell of an isolated atom.
 

 

Well I certainly don't understand the question.

Perhaps because I have never come across an electron that adds up, whatever that means.

That is why you were politely asked for more information.

Though why you should choose to offer petulant insulting remarks to considered comments of help from four different members is beyond me.

Have a nice day.

 

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3 minutes ago, XVV said:

Anyway I just now know that no one can give answers on this website.

Maybe you can post one of the answers from the other sites here? Then I might learn more abut how to interpret the question and what is an acceptable answer, at least according to you. 

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1 minute ago, Ghideon said:

Maybe you can post one of the answers from the other sites here? Then I might learn more abut how to interpret the question and what is an acceptable answer, at least according to you. 

Energy isn't always released when an electron is added to an atom. It depends on the kind of atom you are adding the electron to.

Energy is released if the electronegative atom attains a more stable state by accepting the electron (by say attaining a octet configuration in the valence shell). Stable states have less energy when compared to other states and this difference in energy is released when an atom accepts an electron.

On the other hand, it actually requires energy to add an electron to an electropositive atom which has an extra shell of electrons which makes it unstable. To add another electron we would have to overcome the repulsions due the already present electrons and hence energy would have to be supplied rather than it being released. If by how an electron entere you mean that how does an atom gain or lose electrons,its to complete its octet configuration.For example when Mg reacts with o2 As O has 2 less electrons to reach its octet whilst Mg has 2 extra electrons.Mg gives its electrons to O for both of them to complete their octet.This is known as an Ionic bond.Hope it helps

 

This answer I got from another website. Which is far better than yours.

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Posted (edited)
9 minutes ago, studiot said:

Well I certainly don't understand the question.

He received the same answer, as you and I gave him, on website:

https://physics.stackexchange.com/questions/554525/how-and-why-does-an-electron-add-up-enters-in-the-valance-shell-of-an-atom

..but he did not understand our answers... (and didn't bother about reading articles that we provided, where it is even nicer explained)

9 minutes ago, studiot said:

Perhaps because I have never come across an electron that adds up, whatever that means.

Yes. The inability to speak fluently in English is problematic when discussing such scientific topics.

Edited by Sensei

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5 minutes ago, XVV said:

Anyway I just now know that no one can give answers on this website. your reply proves that I was right about saying that there are more stupid insults instead of good answers.

So someone gave you an answer that you 'like', because it doesn't make you feel inadequate.
Not necessarily the right answer )
And you feel the need to shit on people who are having difficulty understanding your ill-posed question ?

That's a drama queen.
You are welcome to shut the door on your way out, if you don't appreciate it here.

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1 minute ago, Sensei said:

Yes. The inability to speak fluently in English is problematic when discussing such scientific topics.

I have been trying to make allowances for that possibility, both in this thread and the OP's previous thread.

But suddenly the OP bursts forth into fully fledged song, scotching that premise.

(Sorry for the colloquialisms, as you know I am always happy to explain)

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2 minutes ago, MigL said:

So someone gave you an answer that you 'like', because it doesn't make you feel inadequate.
Not necessarily the right answer )
And you feel the need to shit on people who are having difficulty understanding your ill-posed question ?

That's a drama queen.
You are welcome to shut the door on your way out, if you don't appreciate it here.

I feel no joy by coming here. My question is not ill posted. Your mind is c*m filled. It is the right answer

7 minutes ago, Sensei said:

He received the same answer, as you and I gave him, on website:

https://physics.stackexchange.com/questions/554525/how-and-why-does-an-electron-add-up-enters-in-the-valance-shell-of-an-atom

..but he did not understand our answers... (and didn't bother about reading articles that we provided, where it is even nicer explained)

Yes. The inability to speak fluently in English is problematic when discussing such scientific topics.

In the bracket beside it, I wrote (enters).

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!

Moderator Note

Rule 1 (of the rules you agreed to when you joined) is "Be civil"

 

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