The partial electro-oxidation of large silver nanoparticles is evidenced by comparing the charges passed in nanoparticle-electrode impacts at a range of temperatures. For larger silver nanoparticles (> 100 nm diameter), the variation in the charge passed per nano-impact event at higher temperatures demonstrates that single nanoparticles undergo multiple oxidations events at the electrode, and these oxidations do not go to completion. In contrast, the relative insensitivity of the charge passed in the electrode impacts of smaller silver nanoparticles (< 50 nm diameter) to the variation of temperature is consistent with their complete oxidation.