Atoms & Ions Radius: Arranging in Order of Increasing Radius

[msdel]

I am to arrange the following atoms or ions in order of increasing radius...then give an explanation for the position of S2- in relation to the atoms or ions that come before or after it.

Here is what i have so far...in order of increasing radius.

K+
K
O
S2-
Cl

Now I am not sure what they are looking for in an explanation on the rest.

Thanks!

 

[Gokul43201]

What's your reasoning ?

 

[Neha Sanghvi]

Hey msdel,

I think you made a small mistake in arranging the particles in the increasing order of their radius. According to me, it should be :
O
Cl
S2- / K+ ( of the same order )
K

This is according to my knowledge. Any criticism is definitely welcome. Thanks.

 

[SuperChem]

Hey msdel,

I think you made a small mistake in arranging the particles in the increasing order of their radius. According to me, it should be :
O
Cl
S2- / K+ ( of the same order )
K

This is according to my knowledge. Any criticism is definitely welcome. Thanks.

I am inexperienced with this topic aswell,
but i just want to propose something...
Since S^-2 has 16 protons and needs to attract 18 electrons, the electrons are further away from the nucleus than they would be in the case of the Potassium ion K⁺ where 19 protons need to attract 18 electrons. The protons act as a magnet, and attract the electrons closer to the nucleus.

Can anyone correct me, or contradict me? or am i right...

My Answer:

O, Cl, K⁺, S ^-2, K