Boron

Atomic number : 5 Atomic mass : 10.81 g.mol-1 Electronegativity according to Pauling : 2.0 Density : 2.3 g.cm-3 at 20 °C Melting point : 2076 °C Boiling point : 3927 °C Vanderwaals radius : 0.098 nm Ionic radius : 0.027 nm Isotopes : 2 Electronic shell : [He] 2s22p1...

Beryllium

Atomic number : 4 Atomic mass : .9.01218 g.mol-1 Electronegativity according to Pauling : 1.5 Density : 1.86 g.cm-3 Melting point : 1280 °C Boiling point : 2970 °C Vanderwaals radius : unknown Ionic radius : unknown Isotopes : 1 Electronic shell : 1s2 2s2 or [He] 2s2...

Lithium

Atomic number : 3 Atomic mass : 6.941 g.mol-1 Electronegativity according to Pauling : 1.0 Density : 0.53 g.cm-3 at 20 °C Melting point : 180.5 °C Boiling point : 1342 °C Vanderwaals radius : 0.145 nm Ionic radius : 0.06 nm Isotopes : 2 Electronic shell : 1s2 2s1 or...

Helium

Atomic number : 2 Atomic mass : 4.00260 g.mol-1 Electronegativity according to Pauling : 2.1 Density : 0.178*10-3 g.cm-3 at 20 °C Melting point : - 272.2 (26 atm) °C Boiling point : - 268.9 °C Vanderwaals radius : 0.118 nm Ionic radius : unknown Isotopes : 2...

Hydrogen

Facts about Hydrogen The name Hydrogen is derived from the Greek words ‘Hydro’ and ‘Genes’ which together mean ‘Water Forming’ because water molecules contains atoms of hydrogen. It is the lightest element known. It is the most abundant element in the universe. Almost...