5 B 10.81

Boron

METALLOID

Phase: Solid

Discovered: Joseph Louis Gay-Lussac

Block: P

Summary

Boron is a metalloid chemical element with symbol B and atomic number 5. Produced entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, it is a low-abundance element in both the Solar system and the Earth's crust. Boron is concentrated on Earth by the water-solubility of its more common naturally occurring compounds, the borate minerals.

Appearance: black-brown

Source: Wikipedia

Physical Properties

Atomic Mass 10.81 u

Density 2.08 g/cm³

Melting Point 2349 K

Boiling Point 4200 K

Molar Heat 11.087 J/(mol·K)

Electron Affinity 26.989 kJ/mol

Ionization Energies

1^st: 800.6 kJ/mol

2^nd: 2427.1 kJ/mol

3^rd: 3659.7 kJ/mol

4^th: 25025.8 kJ/mol

5^th: 32826.7 kJ/mol