The elements are samarium (Sm) and silver (Ag).
<em>Quantum numbers (4,3,-2,+½) </em>
<em>n</em> = 4: Principal quantum number = 4.
<em>l</em> = 3: Element has 4f electrons
It is <em>conventional</em> to list quantum numbers in decreasing order.
<em>Hund’s rule </em>states that all the orbitals must be half-filled with electrons having the same spin before any can receive a second electron.
We get the following table:
<u>Element </u><em><u>n</u></em><u> </u><em><u>l</u></em><u> </u><em><u>m</u></em><u>ₗ </u><em><u>m</u></em><u>ₛ</u>
La 4 3 3 +½
Ce 4 3 2 +½
Pr 4 3 1 +½
Nd 4 3 0 +½
Pm 4 3 -1 +½
Sm 4 3 -2 +½
The element is samarium, Sm.
<em>Quantum numbers (5,2,-1,-½) </em>
<em>n</em> = 5: Principal quantum number = 5.
<em>l</em> = 2: Element has <em>5d</em> electrons
We get the following table:
<u>Element </u><em><u>n</u></em><u> </u><em><u>l m</u></em><u>ₗ mₛ</u><em><u> </u></em>
<em> </em> Y 5<em> </em>2 2 +½
Zr 5 2 1 +½
Nb 5 2 0 +½
Mo 5 2 -1 +½
Tc 5 2 -2 +½
Ru 5 2 2 -½
Rh 5 2 1 -½
Pd 5 2 0 -½
Ag 5 2 -1 -½
The element is silver, Ag.
<em>Note</em>: These assignments assume that there are <em>no exceptions</em> in the Periodic Table.
