Question

Two electrons are found in the same atom. One has the quantum number set (2, 1, -1, +½), and the other has the quantum number set (2, 1, -1, -½). They share the

a.same sublevel, but are in different orbitals.

b.same orbital, but have different spin directions.

c.same energy level, but are in different sublevels.

d.same type of sublevel, but are found in different energy level

Answer 1

There are four quantum numbers to consider:
1.Principle quantum number (n): describes the energy and the most probable distance from nucleus

2.Orbital angular quantum number (l): describes the shape of the orbital, and can also describe the number of angular nodes.

3.Magenetic quantum number (ml): describes the energy levels in a sub-shell

4.Electron spin quantum number (ms): describes the spin on the electron

In regards to your question you have two electrons:
Electron 1: 2, 1, -1, +1/2
Electron 2: 2, 1, -1, -1/2

the only difference between these two electrons is the quantum number (ms) which designates the spin. Because of this the correct answer is B, same orbital but different spin directions!