Answer
Please see the work below.
Work Step by Step
Boron
The atomic number of B = 5
The correct electronic configuration of Boron = $1s^{2}2s^{2}2p^{1}$
One unpaired electron.
Neon
The atomic number of Neon = 10
The correct electronic configuration of Aluminum = $1s^{2}2s^{2}2p^{6}$
No unpaired electrons.
Phosphorus
The atomic number of P = 15
The correct electronic configuration of P = $1s^{2}2s^{2}2p^{6}3s^{2}3p^{3}$ or $[Ne] 3s^{2}3p^{3}$
Three unpaired electrons.
Scandium
The atomic number of Sc = 21
The correct electronic configuration of Sc = $[Ar]3d^{1}4s^{2}$
One unpaired electron.
Manganese
The atomic number of Mn = 25
The correct electronic configuration of Sc = $[Ar]3d^{5}4s^{2}$
Five unpaired electrons.
Selenium
The atomic number of Se = 34
The correct electronic configuration of Se = $[Ar]3d^{10}4s^{2}4p^{4}$
Two unpaired electrons.
Krypton
The atomic number of Kr = 36
The correct electronic configuration of Kr = $[Ar]3d^{10}4s^{2}4p^{6}$
No unpaired electrons.
Iron
The atomic number of Fe = 26
The correct electronic configuration of Fe = $[Ar]3d^{6}4s^{2}$
No unpaired electrons.
Cadmium
The atomic number of Cd = 48
The correct electronic configuration of Cd = $[Kr]4d^{10}5s^{2}$
No unpaired electrons.
Iodine
The atomic number of I = 53
The correct electronic configuration of I = $[Kr]4d^{10}5s^{2}5p^{5}$
One unpaired electron.
Lead
The atomic number of Pb = 82
The correct electronic configuration of I = $[Xe]4f^{14}5d^{10}6s^{2}6p^{2}$
Two unpaired electrons.
