[futuredentist]

Hello,

I'm working through DAT study materials and was asked a question about ionization energies of Silicon. The question was which ionization energy would be exponentially greater than the previous ionization for Si. The answer was the 5th ionization energy because the electron bus be pulled away from a full p subshell, but then it went through and gave the different ionization energies in kj with the first being 800 kj, the second being 1600 kj, etc.

My question is: How were these numbers determined? Is it information that would be given to be in the question or something I should be able to figure out on my own. Can you point me in the direction to look?

Thanks for your *delete me*

[Borek]

This is basically question about number of valence electrons. Rings a bell?

[futuredentist]

This is basically question about number of valence electrons. Rings a bell?

Yes I think- that as the number of valence electrons increases, it becomes harder to remove one from an atom? This is why the 5th ionization energy is higher than the rest?

[Enthalpy]

A list of all ionisation energies for silicon is here
http://www.webelements.com/silicon/atoms.html
You see a jump when you begin to deplete the second shell (5^th removal), and an other when you begin to deplete the first one (13^th removal).

- The numbers are experimental. Theories are approximations here but give decent figures through heavy computations.
- Here there are qualitative explanations to propose...
- But that was for silicon. Try the same with a transition element and, err, well.

[futuredentist]

A list of all ionisation energies for silicon is here
http://www.webelements.com/silicon/atoms.html
You see a jump when you begin to deplete the second shell (5^th removal), and an other when you begin to deplete the first one (13^th removal).

- The numbers are experimental. Theories are approximations here but give decent figures through heavy computations.
- Here there are qualitative explanations to propose...
- But that was for silicon. Try the same with a transition element and, err, well.

Thank you for your *delete me* I love this site!