Which is not the property of diamond?
A. it is insoluble in all solvents
B. it is oxidised with a mixture of `K_(2)Cr_(2)O_(7)` and `H_(2)SO_(4)` at `200^(@)C`.
C. Being hardest, it is used as an abrasive for sharpening hard tools.
D. `Delta_(f)H^(Theta)` value of diamond is `1.90 kJmol^(-1)`
