[Usernam3]

I have a question, and I have a feeling it's wrong.

Explain why a Cl^- ion is larger than a Cl atom?

You see, I swear a Cl^- ion is smaller, because there are more electrons, to the same nuclear charge, therefore increasing the shells attaction to the nucleus, and therefore decreasing the radius, making the ion smaller in size? Am I wrong, or is the question wrong?

[roar558]

nope due to the extra electron, the attractive forces acting on the outer shell electrons decreases per electron as you have the same number of protons yet more electrons so the size increases

[EierVonSatan]

The ion is larger - you're increasing the number of electrons putting more strain on the nuclei's ability to pull the electron cloud in

The opposite argument holds true that if you remove an electron (from say Na) then the ion is smaller as the nucleus is better able to pull the remaining electrons inwards

[innerhollow]

(Original post by Usernam3)
I have a question, and I have a feeling it's wrong.



You see, I swear a Cl^- ion is smaller, because there are more electrons, to the same nuclear charge, therefore decreasing the shells attaction to the nucleus, and therefore increasing the radius, making the ion larger in size? Am I wrong, or is the question wrong?

Your method of reasoning was correct, but completely inverted.

[areyousure?]

Cl- ion is bigger than the Cl atom.

In metals in the other way round:
Li+ ion is smaller than the Li atiom.

[Jamurai]

Also the electron density in the shell is higher, resulting in more repulsive force so they spread out a bit, therefore larger.

[darbo92]

Larger.

[Usernam3]

I see why now. Cheers people.