. Back to the Page of Chemical Elements . C - Carbon Z=6 . Electron configuration: 1s 2 2s 2 2p 2 . Solar Abundance: 8.55 ? 0.05 (Grevesse et al. 1996) . ION . Spectrum . Configuration . I.P. (eV) . C . CI . 1s 2 2s 2 2p 2 . C + . CII . 1s 2 2s 2 2p . C 2+ . CIII . 1s 2 2s 2 . C 3+ . CIV . 1s 2 2s . C 4+ . CV . 1s 2 . C 5+ . CVI . 1s . References: . Grevesse N., Noels A., Sanyal A.J. 1996, ASP Conf. Series, 99 , 117-126