4. periode
≡
Kalium
K
19
Calcium
Ca
20
Scandium
Sc
21
Titan
Ti
22
Vanadium
V
23
Chrom
Cr
24
Mangan
Mn
25
Eisen
Fe
26
Cobalt
Co
27
Nickel
Ni
28
Kupfer
Cu
29
Zink
Zn
30
Gallium
Ga
31
Germanium
Ge
32
Arsen
As
33
Selen
Se
34
Brom
Br
35
Krypton
Kr
36