4. fas
≡
Kalium
K
19
Kalcium
Ca
20
Skandium
Sc
21
Titan
Ti
22
Vanadin
V
23
Krom
Cr
24
Mangan
Mn
25
Järn
Fe
26
Kobolt
Co
27
Nickel
Ni
28
Koppar
Cu
29
Zink
Zn
30
Gallium
Ga
31
Germanium
Ge
32
Arsenik
As
33
Selen
Se
34
Brom
Br
35
Krypton
Kr
36