1
Hydrogen
H
2
Helium
He
3
Lithium
Li
4
Xenon
Xe
5
Barium
Ba
6
Gold
Au
7
Beryllium
Be
8
Mercury
Hg
9
Boron
B
10
Lead
Pb
11
Carbon
C
12
Radon
Rn
13
Nitrogen
N
14
Radium
Ra
15
Oxygen
O
16
Uranium
U
17
Fluorine
F
18
Neon
Ne
19
Sodium
Na
20
Magnesium
Mg
21
Aluminium
Al
22
Silicon
Si
23
Phosphorus
P
24
Sulfur
S
25
Chlorine
Cl
26
Argon
Ar
27
Potassium
K
28
Calcium
Ca
29
Chronium
Cr
30
Manganese
Mn
31
Iron
Fe
32
Cobalt
Co
33
Nickel
Ni
34
Copper
Cu
35
Zinc
Zn
36
Arsenic
As
37
Branine
Br
38
Krypton
Kr
39
Silver
Ag
40
Iodine
I