Atomic structure and determing effective nuclear charge

[joker314]

Homework Statement

The 3s state of Na has an energy of -5.14 eV. Determine the effective nuclear charge.

Homework Equations

Zeffective = Z - S (not listed in textbook, found this online when trying to figure out the problem)

The Attempt at a Solution

Nothing in the textbook in this section talk about determining nuclear charge. I know that Na is in the 2s$$^{2}$$2p$$^{6}$$ group.

 

[olgranpappy]

For a hydrogenic atom, what is the expression for the energy-levels in terms of the principle quantum-number?

 

[joker314]

I believe that would be 1s

 

[olgranpappy]

I believe that would be 1s

no. you need an equation that relates energy "E" to the principle quantum number "n". Do you know an equation like that?

 

[joker314]

I do now... Even though I read that response too late. The grader of my homework gave me full credit anyways for a sub-par result... But I appreciate the response because it let me on the right track after the fact!