Fig. shows examples of simple O2 oxidation experiments for both a graphite NP and a diamond NP. Identical experiments for graphene oxide, carbon black, and nano-onion NPs are shown in Figs. . Consider the graphite NP experiment in Fig. , where the initial mass was ~39.0 MDa (~37.9 nm diameter for a spherical NP with bulk graphite density (~2.265 g/cm 3 ) ). TNP was initially ramped to 1900 K over a few minutes, then held for ~10 minutes. As the NP was initially heated, contaminants such as methanol or ammonium acetate from the electrospray ionization solution, as well as surface complexes of heteroatoms like O, H, and N, would have desorbed. In addition, when NPs are first heated to high TNP, thermionic electron emission occurs, increasing Q to a new steady-state value. Once TNP had stabilized at 1900 K, the slope of M vs. time was used to determine the raw mass loss rate, -1773 Da/sec. Sublimation dominates the mass loss at 1900 K, and while we have no information about the product species, for bulk graphite a distribution of small Cn species is observed. The nominal (spherical) surface area of this NP was ~4463 nm 2 , giving Rsublimation of ~0.4 Da/sec/nm 2 , and the total mass sublimed was ~1.4 MDa -roughly a monolayer's (ML's) worth of carbon for a spherical NP of this mass.