Question #03b61

1 Answer
Jan 12, 2017

Answer:

Here's why that is the case.

Explanation:

As you know, we can use a total of four quantum numbers, which make up a quantum number set, to describe the location and spin of an electron in an atom.

figures.boundless.com

The notation used for a quantum number set is

#(n, l, m_l, m_s)#

The quantum number set given to you cannot describe an electron in an atom because the value of the angular momentum quantum number, #l#, which gives you the subshell in which the electron resides, is too high.

As you can see, the angular momentum quantum number can take values in the range

#l = {0, 1, 2, ..., n-1}#

where #n#, which is the principal quantum number, tells you the energy level on which the electron resides.

In your case, you have

#(color(red)(n), color(blue)(l), m_l, m_s) = (color(red)(2), color(blue)(2), -1, -1/2)#

Since #color(red)(n=2)#, it follows that #color(blue)(l)# can only take two possible values

#n=2 implies l= {0, 1}#

Since you have #color(blue)(l=2)#, the quantum number set given to you is not possible for an electron in an atom.