Question

What is a possible quantum number set for an electron found in a ground-state helium (He) atom? (1 point)
Select one:
a. (1, 1, 1, +½)
b. (1, 1, 0, -½)
c. (1, 0, 1, -½)
d. (1, 0, 0, +½)

Answer 1

Detailed Explanation: Electronic Configuration of He (Helium) is 1s² which means that 2 electrons are filled in 0 orbital (m = 0) inside s subshell (l = 0) inside 1st Shell (n = 1)

The two electron are having spin quantum numbers where two arrows point in opposite directions. Since s - subshell is filled with two electrons hence,

Upward Electron: 1, 0, 0, + ½

Downward Electron: 1, 0, 0, - ½

In given options only OPTION D match with set of quantum numbers of either electron.

Answer 2

"D" is the right answer.

The four quantum numbers are the principle quantum number, #n#, the angular momentum quantum number, #l#, the magnetic quantum number, #m_l#, and the electron spin quantum number, #m_s#.

The principle quantum number , #n#, describes the energy and distance from the nucleus, and represents the shell.

For example, the #3d# subshell is in the #n=3# shell, the #2s# subshell is in the #n = 2# shell, etc.

The angular momentum quantum number , #l#, describes the shape of the subshell and its orbitals, where #l=0,1,2,3...# corresponds to #s, p, d, # and #f# subshells (containing #s, p, d, f# orbitals), respectively.

For example, the #n=3# shell has subshells of #l=0,1,2#, which means the #n=3# shell contains #s#, #p#, and #d# subshells (each containing their respective orbitals). The #n=2# shell has #l=0,1#, so it contains only #s# and #p# subshells. It is worth noting that each shell has up to #n-1# types of subshells/orbitals.

The magnetic quantum number , #m_l#, describes the orientation of the orbitals (within the subshells) in space. The possible values for #m_l# of any type of orbital (#s,p,d,f...#) is given by any integer value from #-l# to #l#.

So, for a #2p# orbital with #n=2# and #l=1#, we can have #m_1=-1,0,1#. This tells us that the #p# orbital has #3# possible orientations in space.

If you've learned anything about group theory and symmetry in chemistry, for example, you might remember having to deal with various orientations of orbitals. For the #p# orbitals, those are #p_(x)#, #p_(y)#, and #p_(z)#. So, we would say that the #2p# subshell contains three #2p# orbitals .