20 first Elements of the Periodic Table ЁЯШЙ
Aluminum
Element Symbol: Al Atomic Number: 13 Atomic Mass unit: 26.982
Argon
Element Symbol: Ar Atomic Number: 18 Atomic mass unit: 39.948
Boron
Element Symbol: B Atomic Number: 5 Atomic mass unit: 10.811
Beryllium
Element Symbol: Be Atomic Number: 4 Atomic mass unit: 9.0122
Carbon
Element Symbol: C Atomic Number: 6 Atomic mass unit: 12.011
Calcium
Element Symbol: Ca Atomic Number: 20 Atomic mass unit: 40.078
Chlorine
Element Symbol: Cl Atomic Number: 17 Atomic mass unit: 35.453
Fluorine
Element Symbol: F Atomic Number: 9 Atomic mass unit: 18.999
Potassium
Element Symbol: K Atomic Number: 19 Atomic mass unit: 39.098
Magnesium
Element Symbol: Mg Atomic Number: 12 Atomic mass unit: 24.305
Nitrogen
Element Symbol: N Atomic Number: 7 Atomic mass unit: 14.007
Sodium
Element Symbol: Na Atomic Number: 11 Atomic mass unit: 22.990
Neon
Element Symbol: Ne Atomic Number: 10 Atomic mass unit: 20.180
Oxygen
Element Symbol: O Atomic Number: 8 Atomic mass unit: 15.999
Phosphorus
Element Symbol: P Atomic Number: 15 Atomic mass unit: 30.947
Sulphur
Element Symbol: S Atomic Number: 16 Atomic mass unit: 32.065
Silicon
Element Symbol: Si Atomic Number: 14 Atomic mass unit: 28.086
Hydrogen
Element symbol: H Atomic Number: 1 Atomic mass unit: 1.0079
Helium
Element symbol: He Atomic Number: 2 Atomic mass unit: 4.0026
Lithium
Element symbol: Li Atomic Number: 3 Atomic mass unit: 6.941