Suppose that a certain atom possesses only four distinct energy levels. Assuming that all transitions between levels are possible, how many spectral lines will this atom exhibit?
A)three
B)four
C)six
D)unlimited

Question

Suppose that a certain atom possesses only four distinct energy levels. Assuming that all transitions between levels are possible, how many spectral lines will this atom exhibit? 
A)three 
B)four 
C)six 
D)unlimited

Quizplus · Accepted Answer

The number of spectral lines exhibited by an atom is equal to the number of possible transitions between its energy levels. In this case, there are 4 distinct energy levels, so there are 4C2 = 6 possible transitions (choosing 2 levels at a time to form a transition). Therefore, the atom will exhibit 6 spectral lines.

Suppose That a Certain Atom Possesses Only Four Distinct Energy