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Bohr model

Can someone help me with this? I have way too much homework I don't understand. Any way you can help me is fine. Thanks. :smile:

The Bohr model for single electron atoms predicts that the energies of the allowed orbitals are given by: En = (-2.178 * 10^-18) * Zsquared / n squared where n = 1, 2, 3...... and Z is the nuclear charge

i) calculate the minimum energy (in J) required to ionise a ground state hydrogen atom

ii) calculate the wavelength (in nanometres) of the photon emitted by an electron in making the transition from the n=2 to n=1 levels of the single electron ion, He+.

Reply 1

shengoc

The formula for hydrogenic atom is fixed, E = - 13.6/n^2 eV

Change in E(in Joule) = difference between E at n = 1 and n =2 = hf = hc/wavelength

1 ev is roughly 1.6 x 10^-19 J (do the conversion right, you should be able to get the correct answer).