Ionization energy question

[mohad]

So I was running through a couple of practice problems, and one kind of tripped me up.

Whihc of the following elements has the highest ionization energy?

A. Potassium
B. Calcium
C. Scandium
D. Titanium

Apparently, the answer is D, which makes sense if you follow the trends. At least, the book uses the explanation that ionization energy increases as you go right. I thought it was B though because Ca has a stable 4s2 configuration, whereas Sc and Ti have 4s2 3dX. I guess I'm getting confused because there was another question that asked to rank the ionization energies of Lead, Mercury, and Thallium. The order was Hg, Pb, Tl. Hg was the highest because it had a full s and d orbital, and then pb and tl were ranked because they were less stable and followed the trend. Can anyone help clarify this for me?

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[CodeBlu]

Always keep in mind that when they are asking for ionization energy, and they don't specify first or second. They usually mean 1st.

In the case of Calcium... it can form a Ca+ or a Ca++ which would leave it with a full valence shell and looking a lot like Argon.

So Calcium is already gone, as is anything else in group II.

Lets get rid of potassium for the same reason, because it would like to give up that 1 electron to look like Argon also.

Now as for Titanium and Scandium... Titanium has one electron in the 3d subshell and Scandium has 2 electrons in the 3d. Titanium doesn't want to give up that 3d electron, because its closer to the nucleus than the 4S shell. So knowing this... Titanium has a higher ionization energy.

 

[whiteshadodw]

Always keep in mind that when they are asking for ionization energy, and they don't specify first or second. They usually mean 1st.

In the case of Calcium... it can form a Ca+ or a Ca++ which would leave it with a full valence shell and looking a lot like Argon.

So Calcium is already gone, as is anything else in group II.

Lets get rid of potassium for the same reason, because it would like to give up that 1 electron to look like Argon also.

Now as for Titanium and Scandium... Titanium has one electron in the 3d subshell and Scandium has 2 electrons in the 3d. Titanium doesn't want to give up that 3d electron, because its closer to the nucleus than the 4S shell. So knowing this... Titanium has a higher ionization energy.

i think you got them mixed up:

Ti: [Ar] 4s2 3d2
Sc: [Ar] 4s2 3d1

i would pick Ti because the Zeff has increased, one more proton in Ti than Sc. The extra electron in the d orbital doesn't matter because both Ti and Sc have the same number of core electrons.

 

[CodeBlu]

i think you got them mixed up:

Ti: [Ar] 4s2 3d2
Sc: [Ar] 4s2 3d1

i would pick Ti because the Zeff has increased, one more proton in Ti than Sc. The extra electron in the d orbital doesn't matter because both Ti and Sc have the same number of core electrons.

So very true.
Note to self: Do not post on SDN when on oxycodone for wisdom teeth, you are not Dr. House, you are not Dr. House....

 

[whiteshadodw]

So very true.
Note to self: Do not post on SDN when on oxycodone for wisdom teeth, you are not Dr. House, you are not Dr. House....

😛 i LOVE oxycodone. i have a bottle of the super powerful stuff from my ACL reconstruction. but that stuff makes you so lethargic and stuff. would totally kill my MCAT prep even if i took one.

on a side note, for any elements that are in the same row, i would generally say that they all have the same number of core electrons.

 

[CodeBlu]

😛 i LOVE oxycodone. i have a bottle of the super powerful stuff from my ACL reconstruction. but that stuff makes you so lethargic and stuff. would totally kill my MCAT prep even if i took one.

on a side note, for any elements that are in the same row, i would generally say that they all have the same number of core electrons.

As in oxycontin? The continuous release oxy? If so... that stuff is dangerous. Addictive potential through the roof. Save that stuff for a rainy day of insane migraines etc.

I'm on the PG oxycodone/acetaminophen (5mg/325mg). Also, I've done a fair bit of ortho shadowing, I know how painful ACL reconstructions can be. Hope your taking care of it now.

 

[MT Headed]

So I was running through a couple of practice problems, and one kind of tripped me up.

Whihc of the following elements has the highest ionization energy?

A. Potassium
B. Calcium
C. Scandium
D. Titanium

This question would be difficult to ansswer quickly if you don't know BEANS.

http://forums.studentdoctor.net/showpost.php?p=9942901&postcount=3

I've used this mnemonic dozens of times, it is quire handy.

 

[bullsfan1986]

So very true.
Note to self: Do not post on SDN when on oxycodone for wisdom teeth, you are not Dr. House, you are not Dr. House....

They gave you oxycodone for wisdom teeth??? (Just surprised since they usually prescribe hydrocodone/APAP for things like that.) I want to go to your doctor

 

[CodeBlu]

They gave you oxycodone for wisdom teeth??? (Just surprised since they usually prescribe hydrocodone/APAP for things like that.) I want to go to your doctor

I had a ridiculous case... Some odd reason I had 2 sets of wisdom teeth. Weird right? 3 out of the 8 were impacted.