some gchem questions

[thehonya]

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So I'm not getting this question. Wouldn't Ni only have 4 valence electrons because the 4th shell is the highest energy and thus all the other shells are core electrons?

Also, I was wondering why Nitrogen can bind to fewer bonds than Phosphorus. It seems to me that they are in the same group and thus can bind the same amount of atoms.

 

[TraumaBlonde]

I'm looking in my files to find an article to explain if but basically, ones a slut and the other one is more prude- in vernacular

 

[tyunup]

Chad has some details about it on his forum http://www.coursesaver.com/showthread.php?5640-Valence-Electrons

Basically, because Ni doesn't have a full 3d shell, the d electrons are also counted as valence electrons as well. Its only if the 3d shell is completely full would the d's not be considered part of the valence shell. So because Ni has 4s2 and 3d8, it has ten valence.

Because nitrogen is in the second period, it can't have more than 8 total shared electrons, which is why NO3- has the lewis structure it has. Phosphorus is in the 3rd period, and when you get to the third period the element has access to the d subshells for storage of extra electrons, so phosphorous can have more than 8 electrons. Look up the lewis dot structures of NO3- and PF5 and count the total shared electrons to see. In NO3- there are only eight electrons assoc with N, and in PF5 there are 10 electrons associated with P

 

[TraumaBlonde]

That was a perfect description ^