Question

question 23 (1 point)
which of the following neutral atoms has three unpaired electrons?
ai
se
ge
sb

Explanation:

• For \(Al\) (atomic number \(13\)): Electron configuration is \([Ne]3s^{2}3p^{1}\). There is \(1\) unpaired electron in the \(3p\) orbital.
• For \(Se\) (atomic number \(34\)): Electron configuration is \([Ar]3d^{10}4s^{2}4p^{4}\). In the \(4p\) sub - shell (with \(3\) orbitals, \(p_x\), \(p_y\), \(p_z\)), according to Hund's rule, electrons first fill each orbital singly. Here, there are \(2\) unpaired electrons in the \(4p\) orbitals.
• For \(Ge\) (atomic number \(32\)): Electron configuration is \([Ar]3d^{10}4s^{2}4p^{2}\). There are \(2\) unpaired electrons in the \(4p\) orbitals.
• For \(Sb\) (atomic number \(51\)): Electron configuration is \([Kr]4d^{10}5s^{2}5p^{3}\). In the \(5p\) sub - shell (three \(p\) orbitals), according to Hund's rule (electrons fill degenerate orbitals singly before pairing), there are \(3\) unpaired electrons in the \(5p\) orbitals.

Answer:

Sb.