Destroyer GC # 256 (2012)

[Heller123]

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I dont quite understand how the strontium cation is smaller than a sulfur anion? Even if it is a cation (Sr++) against an anion (S--) wouldn't strontium be bigger since it still has more electrons overall? 😕

 

[mario0923]

it should be an error
it would have made sense if the cation was Ca2+ not Sr2+

 

[votruong]

I agreed, it should be an error. S-- should be smaller than Sr++

 

[njdoc327]

.

 

[Heller123]

Wow! I was staring at this for 20 minutes trying to figure it out! I even rewatched Chad's to see if I missed something

Thanks guys!

 

[Kingsta2426]

No, its not an error, cations are always smaller than neutral or negatively charged species because they hold their electrons closer to the nucleus which reduces the size/radius.

 

[njdoc327]

yeah kingsta is right. all anions are larger than cations. so as you should probably already know, an anion means that there is an extra electron. well when that extra electron enters an orbital, there is more electron-electron repulsions which spread them even further apart. this happens when electrons outnumber the protons. now on the other hand, when there are more protons than electrons, the repulsions will go the other way. the protons outnumber the electrons which causes the electrons to be attracted to them and move closer to the nucleus.

hope that makes sense.

 

[Heller123]

Yup! Found an old post answering my question. Thanks for the correction

http://forums.studentdoctor.net/showthread.php?t=701730