1. How many different sets of quantum numbers are possible for an electron for which:

a) n=1

b) n=2

c)n=3

d)n=4

e)n=5

2. For a hydrogen atom in its ground state, use the Bohr model to compute:

a) the orbital speed of the electron

b) the KE of the electron

c) the electrical potential energy of the atom

3. A monoenergetic bema of electrons is incident on a single slit of width 0.500nm. A diffraction pattern is formed on a screen 20.0cm from the slit. If the distance between successive minima of the diffraction pattern is 2.10cm, what is the energy of the incident electrons?

Thanks for any help you can give!