The elemental substances of boron (denote B) Allotropes(同素异形体)：amorphous B-→brown powder (a few types)crystalline B->black-gray Properties:high chemical activity,high hardness high m.p and b.p a一菱形硼(B12)(one of the crystalline type of B): Atomic crystal 12 vertices,20 facesThe elemental substances of boron (denote B) Allotropes(同素异形体)：amorphous B  brown powder (a few types) crystalline B  black-gray Properties: high chemical activity, high hardness high m.p and b.p α -菱形硼 (B12) (one of the crystalline type of B): Atomic crystal 12 vertices, 20 faces