Hydrogen atom wavelengths and energy levels using the Rydberg formula

[HjGanap]

Homework Statement

the wavelengths of the emission lines produced by the hydrogen atom are given by the formula:

1/lambda = 1.096776 x 10^-2 ((1/n2^2) - (1/n1^2)) nm^-1

(a) what are the wavelengths of the first two lines in the Balmer series, H-alpha and H-beta (involving transitions to level n=2) ?

(b) calculate the energy in eV required to raise an electron from the ground state to level 2.

(c) electrons of energy 12.9 eV are fired at H atoms in a gas discharge tube. if initially all the atoms are in the ground state, what is the highest level to which the electrons in the atom can be excited? what is the longest wavelength of the possible level transitions that may then follow?

Homework Equations

as mentioned above

The Attempt at a Solution

by using data from energy-level diagram, but, confused which 1 to use for the values of n.

 

[Redbelly98]

(a)
Since these are emission lines, the electron goes from a higher n1 to a lower n2. The lower n2, as it says, is 2.