1.     When an electron moves from the n = 7 orbit to the n = 5 orbit of a 

hydrogen atom, a photon of light is emitted.

1. What is the energy of this photon, in Joules?
2. What is the frequency of this photon, in Hertz?
3. What is the wavelength of this photon, in nanometers?

(Eel = -2.18 x 10-18 J / n2.    h = 6.63 x 10-34 Joule sec.        

C = 3.00 x 108 m / sec.    1 m = 1 x 109 nm.)

2.     How many electrons in an atom of argon (Ar) have:

a) a value of 1 for the azimuthal quantum number, l ?

b) a value of -1/2 for the spin quantum number, ms ?

3.     What kinds of covalent bonds - single, double, or triple - are present in:

a) a molecule of OCS  (C = central atom) b) the NO +1 ion