Boron

| Introduction | History | Other Periodic Tables | Back |

Symbol:

B

Atomic Number:

5

Relative Atomic Mass:

10.811 g mol^-1

Natural Abundance in Lithosphere, hydrosphere and atmosphere:

10^-3% (mass fraction)

Electron Configuration:

[He]2s²2p

Oxidation States:

III

Atomic Radius:

79.5pm

Covalent Radius:

81pm

Ionic Radius:

1pm (for +3 oxidation state, 3 coordinate)

11pm (for +3 oxidation state, 4 coordinate)

Melting Point:

2180°C

Density:

2.35 g cm^-3 (at 20°C)

First Ionisation Energy:

8.298 eV

Electronegativity (Allred and Rochow):

2.0

Number of Natural Isotopes:

2

Mass Number of the Most Abundant Isotopes:

10 g mol^-1 a 19.9% abundance

11 g mol^-1 a 80.1% abundance