Chapter 2, #93

[donnanguyen1d]

How come Na becomes a larger circle and Cl is a smaller circle? how do the charges come into play?

[David Minasyan 1C]

Isn't it the other way around? Cl becomes the larger circle because it gains an electron and it's greater than its ground state because of that gained electron whereas Na loses that electron to Cl and becomes the smaller circle.

[Priyanka Bhakta 1L]

Yes, as David said, the Na+ ion (and all cations) becomes smaller because it loses an electron, which means there is less electron repulsion, and the electrons left are more attracted to the nucleus which results in a smaller atom. On the other hand, the Cl- ion (and all anions) becomes larger than its parent atom because it gains an electron which causes more repulsion, electrons are pushed further from the nucleus and thus, the radius increases and results in a larger atom.

Hope this helps clear things up!

[JamesAntonios 1E]

When in ground state and having lost or gained no electrons, atomic radius increases from right to left and down. However, when ions come into play, because those on the right of the periodic table gain electrons, they have an expanded shell and thus have a larger radius than cations. But, in all, atomic radius still increase down the radius. Hope this helps!