1st, 2nd, 3rd ionization energies

[fdat94]

can someone please explain to me how this works? very difficult

thanks!

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[rdub]

Chad explains this very well. We know that Boron has 3 valence electrons. These 3 valence electrons are the furthest away from the positively charged nucleus of the atom. We know that electrons are naturally attracted to the nucleus (+ and - charges attract). Because the valence electrons feel the least amount of attraction compared to the core electrons (because they are furthest away), they are the easiest to remove from the atom. This is why valence electrons have the lowest ionization energy (less energy is required to pull them away from the atom).

Each time you pull one electron off, the atom gets slightly smaller, and so it becomes even harder (requires more energy) to remove the second electron. For boron, the first 3 electrons will only have a slightly different ionization energy (the 2nd has slightly more than the first, etc.) But the fourth one is a core electron, so it takes MUCH more energy to pull it away. Because of this, you will see a huge jump in ionization energy from the 3rd to the 4th electron in boron.

 

[fdat94]

Chad explains this very well. We know that Boron has 3 valence electrons. These 3 valence electrons are the furthest away from the positively charged nucleus of the atom. We know that electrons are naturally attracted to the nucleus (+ and - charges attract). Because the valence electrons feel the least amount of attraction compared to the core electrons (because they are furthest away), they are the easiest to remove from the atom. This is why valence electrons have the lowest ionization energy (less energy is required to pull them away from the atom).

Each time you pull one electron off, the atom gets slightly smaller, and so it becomes even harder (requires more energy) to remove the second electron. For boron, the first 3 electrons will only have a slightly different ionization energy (the 2nd has slightly more than the first, etc.) But the fourth one is a core electron, so it takes MUCH more energy to pull it away. Because of this, you will see a huge jump in ionization energy from the 3rd to the 4th electron in boron.

thanks, yeah I saw what chad said about it and it totally makes sense to me,
Where i get really confused is that when the question would ask whats the lowest or highest 3rd or 1st ionization energies of given atoms

 

[rdub]

thanks, yeah I saw what chad said about it and it totally makes sense to me,
Where i get really confused is that when the question would ask whats the lowest or highest 3rd or 1st ionization energies of given atoms

Could you post a sample question?

 

[fdat94]

Could you post a sample question?

this is from chad's quizzes

 

[rdub]

this is from chad's quizzes

Look at each atom and see which one would take the most energy to remove the second electron from. Does that make sense? For example, Carbon has 4 valence electrons and so you know that it will not have a high 2nd ionization energy (it will have a high 5th ionization energy).

I'm guessing the answer is sodium, because it only has 1 valence electron, so the 2nd ionization energy will be really high because it is for a core electron.

 

[fdat94]

Look at each atom and see which one would take the most energy to remove the second electron from. Does that make sense? For example, Carbon has 4 valence electrons and so you know that it will not have a high 2nd ionization energy (it will have a high 5th ionization energy).

I'm guessing the answer is sodium, because it only has 1 valence electron, so the 2nd ionization energy will be really high because it is for a core electron.

Yes! makes sense now

and what if the question asked, what is the lowest 1st ionization energy? how would i approach that

 

[rdub]

Yes! makes sense now

and what if the question asked, what is the lowest 1st ionization energy? how would i approach that

Then it is essentially asking which atom is the easiest to remove an electron from. In that case, if it is comparing atoms which all have one valence electron, you will likely be looking for the biggest atom. The bigger the atom, the further away the valence electron is from the nucleus, and the easiest it is to remove.

 

[fdat94]

Then it is essentially asking which atom is the easiest to remove an electron from. In that case, if it is comparing atoms which all have one valence electron, you will likely be looking for the biggest atom. The bigger the atom, the further away the valence electron is from the nucleus, and the easiest it is to remove.

Interesting, I am going to have to let that sink it

I hope they dont ask me that next friday on the DAT :|

Thanks for all your help

 

[rdub]

Interesting, I am going to have to let that sink it

I hope they dont ask me that next friday on the DAT :|

Thanks for all your help

Once you understand it, it is actually one of the easiest/quickest questions to answer. Good luck

 

[Alpha Centauri]

Once you understand it, it is actually one of the easiest/quickest questions to answer. Good luck

I hate to bump an old thread but I wanted to ask instead of making a brand new thread. Which would have a higher second ionization energy, Rb or Cs?

 

[DMikes]

I hate to bump an old thread but I wanted to ask instead of making a brand new thread. Which would have a higher second ionization energy, Rb or Cs?

Rubidium, I believe.

 

[DMikes]

They both would have relatively high ionization energies, but rubidium is smaller (electrons closer to nucleus) and would require more E to remove. Somebody correct me if i'm wrong!

Remember ionization energy increases up and to the right. (toward fluorine)

 

[Alpha Centauri]

They both would have relatively high ionization energies, but rubidium is smaller (electrons closer to nucleus) and would require more E to remove. Somebody correct me if i'm wrong!

Remember ionization energy increases up and to the right. (toward fluorine)

And you are talking about the second not first ionization energy right? I know first IE increases up and to the right, and second IE increases left and downwards, so I am confused as to Cs would have a smaller 2nd IE as opposed to Rb, which is 1 element higher and therefore, according to the trend, have a smaller 2nd IE

 

[DMikes]

The up right trend doesn't necessarily apply for second ionization energies, but since you're comparing atoms with the same number of valence electrons I think it still works to a degree. I've never heard of the second IE left and down, to be honest, so i'm not sure how accurate that is.