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:
Group
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
#
Name19
K20
Ca21
Sc22
Ti23
V24
Cr25
Mn26
Fe27
Co28
Ni29
Cu30
Zn31
Ga32
Ge33
As34
Se35
Br36
Kr
e--conf.
Alkali metals Alkaline earths Lanthanide Actinides Transition metals Other metals Metalloids Nonmetals Halogens Noble gases