1
H
1
3
Li
7
2
He
4
20
Ca
40
4
Be
9
5
B
11
6
C
12
7
N
14
8
O
16
9
F
19
10
Ne
20
11
Na
23
12
Mg
24
13
Al
27
14
Si
28
15
P
31
16
S
32
17
Cl
35.5
18
Ar
40
19
K
39
Build Your Own Twenty Element Periodic Table
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