Stable isotope Boron (B)

Isotope Atomic Mass Natural Abundance Nuclear Spin Nuclear Magnetic Moment
B-10 10.0129370 19.90% 3 1.80065
B-11 11.0093055 80.10% 3/2 2.688637

Properties of Boron

Name Boron
Symbol B
Atomic number 5
Atomic weight 10.811
Standard state Solid at 298 °K
CAS Registry ID 7440-42-8
Group in periodic table 13
Group name None
Period in periodic table 2
Block in periodic table p-block
Color Black
Classification Semi-metallic
Melting point 2075 °C
Boiling point 2550 °C
Vaporization point 4000 °C
Thermal conductivity 0.274  W/(m·K) at  298.2 °K
Electrical resistivity 1.8 x 1012 µΩ·cm at 0 ºC; 3.0 x 106 Ω·cm at 100 ºC
Electronegativity 2.0
Specific heat 1030 J/(kg·K)
Heat of vaporization 507 kJ·mol-1 at 2550 ºC
Heat of fusion 50 kJ·mol-1
Density of solid 2.34 cryst. g/cm3
Density of powder 2.45 g/cm3
Electron configuration [He]2s22p
Oxidation state +3
Mohs hardness scale 9.3