$\left[\begin{array}{c}{\mathrm{C}}_{\left(\mathrm{graphite}\right)}+{\mathrm{O}}_{2\left(\mathrm{g}\right)}\to {\mathrm{CO}}_{2\left(\mathrm{g}\right) }∆\mathrm{H}=-393.5\mathrm{KJ}\\ {\mathrm{C}}_{\left(\mathrm{diamond}\right)}+{\mathrm{O}}_{2\left(\mathrm{g}\right)}\to {\mathrm{CO}}_{2\left(\mathrm{g}\right) }∆\mathrm{H}=-395.4\mathrm{KJ}\end{array}\right]$

between ${\mathrm{C}}_{\mathrm{graphite}} \mathrm{and} {\mathrm{C}}_{\mathrm{diamond} }$which one is stable allotropic form of carbon