Which requires the highest first ionization energy?

[Tina324]

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Na+ or Ne?
I think Na+ because Na+ and Ne are isoelectronic, but Na has one more proton that is able to pull the electrons in closer.
Is my reasoning correct?

Mg+ or Al?
I would think since Al is smaller than Mg+, it would have a higher ionization nrg, but Mg+ actually does =/. What's the reasoning behind this? how do you figure it out if the two atoms are not isoelectronic?

 

[DDS13]

Na+ or Ne?
I think Na+ because Na+ and Ne are isoelectronic, but Na has one more proton that is able to pull the electrons in closer.
Is my reasoning correct?

Mg+ or Al?
I would think since Al is smaller than Mg+, it would have a higher ionization nrg, but Mg+ actually does =/. What's the reasoning behind this? how do you figure it out if the two atoms are not isoelectronic?

--- for the first one, since they are both isotonic, i would think, we can go with periodic trend and say Ne has highest first ie. is the answer Na?

--- for the second one, mg+ will loose 2 more electron to be very stable and isoelectronic with an inert gas, so i think that is why.

anyone strong in gchem can answer this??? it is very importang

 

[tranv117]

Na+ would have a higher 1st ionization energy compared to Ne. Really, the ionization energy of Na+ would already be considered its second ionization energy and would definately be higher then the 1st ionization energy of Ne.

You can also think of it as Na having one more nuclear proton compared to Ne. Comparing Na+ and Ne, both with 8 valence electrons, the extra proton in Na would definately pull the electrons closer to the nucleus hence much harder to pull off that electron. Hope that makes sense. Na+ has a greater Zeff(nuclear effective charge) compared to Ne.

As for the second one, Im not too sure. I think the position between the two on the P table is a bit too far apart to really be able to come up with a conclusion without any data. Maybe someone else here can give an explanation for that.

 

[tranv117]

For the second one, Mg+ wants to pull that electron off to have a complete octet so a farely low ionization energy. BUT, it would be its second ionization energy and still would be higher then Mg losing its 1st electron to be Mg+.

But comparing this with Al, not too sure. I mean if you were to compare Mg and Al, then Al definately has the higher first ionization energy. But Al and Mg+ is a little different.

 

[Tina324]

cool that's wat I thought for the frist one. Na+ needs more energy cuz of the proton.

with the second one..it's from achiever test #2 and the answer is that Mg+ requires more energy than Al to remove its outmost electron.
I could go either way on this one, so does anybody know why?

 

[Tina324]

ohhhh i think i get it..damn thsi is hard. someone PLEASEEE verify..and post mroe of these q's if u have them.

Ok Mg+ has 11 electrons and 12 protons
and Al has 13 electrons and 13 protons.

so since Mg+ has a great ratio of protons/electrons than Al, Mg+ has a stronger pull on its electrons, so it needs more energy.

 

[tranv117]

Most likely it's because Mg+ is the second ionization energy. I thought I read somewhere that typically the 2nd would be much higher then the 1st, esp when comparing two elements that are this close in atomic number on the P. table

 

[joonkimdds]

errr this is hard.

 

[tranv117]

1st ionization energy is going from the ground state (Na). After the 1st, you have Na+. 2nd would be removing another electron to Na2+. Ionization energy is the energy needed to remove and electron not add an electron.