Regarding Electron Energy?

Question

I have a question regarding the energy needed to raise an electron a level (from level 2 to level 3). I'm pretty sure you use the equation (E = -Rhc/n^2) but I'm not sure which number to put into the "n" value, and better yet, I'm getting an answer that isn't on the sheet for either using 2 or 3 for the n value! Is there something wrong w/ this equation or am I doing something wrong?

Answer 1

The Rydburg formula is:

1/λ = R Z² ( 1/m² - 1/n²)

where m < n, R is the Rydburg constant, Z is the atomic number (number of protons in the nucleus). E = h f, and f λ = c, so that, letting m = 0, we have

E = - R hc Z² / n² = - R hc / n²

only when Z = 1, as for hydrogen atoms, and only when m = 0. Check your values for Z and m? Maybe they're something else?

Addendum: fink maybe has got the answer to your problem, you need to use both m and n.

Answer 2

i know the equation to bring an electron from the excited state to ground state is E= -13.6/n^2. N normally represents the number of energy levels passed, like if it was from 3 to 2, n would equal 1, if it was 4 to 1, n would equal 3