Element Symbol Atomic No. Electronic Configuration Oxidation States
Atomic Radius
1st Ionization
(pm) Energy (kJ
Scandium Sc 21 [Ar] 3d1 4s2 +3 162 631
Titanium Ti 22 [Ar] 3d2 4s2 +2, +3, +4 147 658
Vanadium V 23 [Ar] 3d3 4s2 +2, +3, +4, +5 134 650
Chromium Cr 24 [Ar] 3d5 4s1 +2, +3, +6 128 652
Manganese Mn 25 [Ar] 3d5 4s2 +2, +3, +4, +6, +7 127 717
Iron Fe 26 [Ar] 3d6 4s2 +2, +3, +4, +6 126 762
Cobalt Co 27 [Ar] 3d7 4s2 +2, +3, +4 125 758
Nickel Ni 28 [Ar] 3d8 4s2 +2, +3 124 737
Copper Cu 29 [Ar] 3d10 4s1 +1, +2 128 745
Zinc Zn 30 [Ar] 3d10 4s2 +2 139 906