1
hydrogen (H)
2
helium (He)
3
lithium (Li)
4
beryllium (Be)
5
boron (B)
6
carbon (C)
7
nitrogen (N)
8
oxygen (O)
9
fluorine (F)
10
neon (Ne)
11
sodium (Na)
12
magnesium (Mg)
13
aluminum (Al)
14
silicon (Si)
15
phosphorous (P)
16
sulfur (S)
17
chlorine (Cl)
18
argon (Ar)
19
potassium (K)
20
calcium (Ca)
21
scandium (Sc)
22
titanium (Ti)
23
vanadium (V)
24
chromium (Cr)