Platinum, which is widely used as a catalyst, has a work function φ(the minimum energy needed to eject an electron from the metal surface) of 9.05 x 10-19 . what is the longest wavelength of light which will cause electrons to be emitted?
a. 2.196×10-7m
b. 4.553×10-6 m
c. 5.654 x 102 m
d. 1.370 x 1015 m
e. > 106 nm