Homework Problem #7.75b

[MaddyCowan3F]

Just wanted to clarify, why is carbon "atomized," and what does this mean? I understand how to complete the rest of the problem using bond enthalpies, but don't understand where the value 717 kJ/mol is taken from

[Neil DSilva 1L]

Bond enthalpies are calculated when all the substances are in the gas phase, but the problem has carbon in the solid phase (as graphite). The atomization of carbon is just the energy required to turn the graphite into gaseous carbon (it's essentially another way of saying sublimation), so all the substances in the problem are then in the gas phase.

[Maria Davila 2I]

Atomization is basically in this case the energy required to turned carbon (graphite) from its solid state into its gaseous state.