Is Electronegativity Applicable to Ions?

In summary: Effective nuclear charge.In summary, the electronegativities of ions, such as O-, N+, S-, O+ can be compared by looking at the size factor, the number of electrons in the valence shell, and the charge of the nucleus.
  • #1
zorro
1,384
0
Is there any method to compare the electronegativity of ions such as O-, N+, S-, O+?
 
Chemistry news on Phys.org
  • #2
Sure. Think about what plays a role in the electronegativities of atoms, for example, why is F more electronegative than H?
 
  • #3
F is more electronegative because it has smaller radius w.r.t H.
So I presume you mean size factor will play a role in electronegativity.
Consider these ions-

O (8en & 8p), O+ (7en & 8p), N+ (6en & 7p), N (7en & 7p)

Here how do you determine the sizes?
I have a method to find out the sizes of isoelectronic species. No idea about this one.
 
  • #4
Right, it has to do with radius, but also the number of electrons shielding the nucleus and the charge of the nucleus itself. Think of it like this: F has very few electrons between the "edge" of the atom and the nucleus, and the nucleus has 9 protons (which are charged).

When dealing with ions, look at the number of electrons in the valence shell, the number of electrons in non-valence shells (i.e. how will these shield attraction effects from the nucleus on the valence electrons?) and the charge of the nucleus itself. For example, in an anion, there are more valence electrons than in its respective neutral atom, so the total nuclear charge is less than the charge of the valence electrons. This means that the electrons will not be "pulled in" towards the nucleus as much, resulting in a higher radius.

So using this information, would you guess that O is more or less electronegative than O+?
 
  • #5
You are explaining a method to compare the radius of an atom and its ion (which I already know)
What I asked was how do you compare ( in other words arrange) ions of different atoms in the increasing order/decreasing order of electronegativies. Like-


O (8en & 8p), O+ (7en & 8p), N+ (6en & 7p), N (7en & 7p)
 
  • #6
My fault, sorry for the misunderstanding.

When you're looking at O and N, they're very close to each other on the periodic table, so the electronegativity difference between the neutral atom and the ion is going to be about the same. You know that O+ and N+ are more electronegative than their neutral atoms, and that O is more electronegative than N. So from here, you look at the difference in electronegativity between the two neutral atoms (I think it's around 0.4-0.5). I'm not sure of the exact number, but the change in electronegativity from a neutral atom to its cation is pretty small. So for the case you gave, the order (decreasing) is O+, O, N+, N. Does that make sense?
 
  • #7
pzona said:
the order (decreasing) is O+, O, N+, N. Does that make sense?

No it doesn't. The correct answer is O+ > N+ > O > N.
 
  • #8
Alright, so it's been a while since I've done electronegativities of atoms vs. ions.

I suppose the ratio of protons to electrons comes into play here. Since you're dealing with fairly small numbers (6, 7, 8) a difference of one electron will make a bigger difference than I expected. Let me check my gen chem text and see if I can find anything, and I'll get back to you.

If anyone else has input on this feel free to help; clearly I don't know as much about this as I thought.
 
  • #9
Abdul Quadeer said:
No it doesn't. The correct answer is O+ > N+ > O > N.

electronegativity is a measure of the ability of an atom to attract Bonding electrons in a molecule. So i believe that this term is not defined on ION. I believe you are talking about effective nuclear charge, so the arrangement is correct. Electronegativity is a hypothetical value based on Maths, so different scientists have diff ways of calculating it thus give rise to different scales.
 
  • #10
gerrardz said:
electronegativity is a measure of the ability of an atom to attract Bonding electrons in a molecule. So i believe that this term is not defined on ION. I believe you are talking about effective nuclear charge, so the arrangement is correct. Electronegativity is a hypothetical value based on Maths, so different scientists have diff ways of calculating it thus give rise to different scales.

Yes it is true. This debate is meaningless by definition of electronegativity>
 

1. What is electronegativity?

Electronegativity is a measure of an atom's ability to attract and hold onto electrons in a chemical bond. It is a fundamental property of elements that helps predict the behavior of chemical compounds.

2. How is electronegativity of ions different from electronegativity of atoms?

The electronegativity of ions refers to the ability of an ion to attract electrons, while the electronegativity of atoms refers to the ability of an individual atom to attract electrons. Ions have different electronegativities compared to their parent atoms due to the change in their electron configuration.

3. How is the electronegativity of an ion determined?

The electronegativity of an ion is determined by several factors, including the number of protons and the distance between the nucleus and the valence electrons. Generally, the smaller the ion and the higher the charge, the higher the electronegativity.

4. How does electronegativity affect bonding between ions?

Electronegativity plays a crucial role in determining the type of bond that forms between ions. If the difference in electronegativity between two ions is large, an ionic bond will form, where one ion completely transfers electrons to the other. If the difference is small, a covalent bond may form, where the electrons are shared between the ions.

5. Can the electronegativity of an ion change?

Yes, the electronegativity of an ion can change depending on its chemical environment. For example, the electronegativity of an ion may increase if it is surrounded by atoms with higher electronegativities, leading to a stronger attraction for electrons. Additionally, the oxidation state of an ion can also affect its electronegativity.

Similar threads

Central atoms in Lewis structures: basic question
    • Chemistry
Replies
4
Views
353
Regenerating ion exchange resin
    • Chemistry
Replies
2
Views
630
Does high electronegativity mean low electropositivity?
    • Chemistry
Replies
10
Views
981
Non polar molecule with polar bonds?
    • Chemistry
Replies
34
Views
2K
Electrochemistry and cell electroplating
    • Chemistry
Replies
4
Views
2K
A new scale for electronegativity
    • Chemistry
Replies
3
Views
3K
What's the chemistry behind a semiconductor?
    • Chemistry
Replies
8
Views
986
Questions about the common-ion effect
    • Chemistry
Replies
4
Views
802
Why does an alkoxide steal H from water?
    • Chemistry
Replies
11
Views
2K
Daniell cell initial equilibrium
    • Chemistry
Replies
4
Views
2K

Hot Threads

Recent Insights

Back
Top