Boron exist in different allotropic forms .All allotropic fropm contains icosahedral units (icosahedral is a regular shape with 12 corners and 20 faces ) with boron atoms at all 12 corners and all bonds are equivalent .
Calculate `DeltaH` (n KJ) per mole of boron atoms formating gaseous icosahedron if `DeltaH_(BE)(B-B)=200KJ//mol:`
A. 1000
B. 600
C. 500
D. 250
