Question

The probability that an electron will return to a lower energy level by emitting a photon is called
a. spontaneous emission
b. line emission
c. the Bohr radius
d. the ground state

I thought it was A and I looked it up online and it had A but I put it on one of my quizzes and got it marked wrong. My teacher circled C.

http://en.wikipedia.org/wiki/Spontaneous_emission