A period 4 element is one of the chemical elements in the fourth row (or period) of the periodic table of the elements.

These are:

Chemical elements in the fourth period
Group 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
#
Name
19
K
20
Ca
21
Sc
22
Ti
23
V
24
Cr
25
Mn
26
Fe
27
Co
28
Ni
29
Cu
30
Zn
31
Ga
32
Ge
33
As
34
Se
35
Br
36
Kr
e--conf

Alkali metalsAlkaline earthsLanthanideActinidesTransition metals
Other metalsMetalloidsNonmetalsHalogensNoble gases

Period 1 element - Period 2 element - Period 3 element - Period 4 element - Period 5 element - Period 6 element - Period 7 element - Period 8 element -