Chemical prefixes are used to denote the presence of certain elements in a compound. Aceto, oxy, TRI, STEREO, oxo, petro, eka, eth, iso, oxa, tol, fluo, phen, sila, glyco, metho, pheno, and sodio are all chemical prefixes. Aceto is a five letter prefix meaning 'containing acetic acid'. Oxy is a three letter prefix meaning 'containing oxygen'. TRI is a three letter prefix meaning 'three atoms'. STEREO is a six letter prefix meaning 'three dimensional'. Oxo is a three letter prefix meaning 'containing oxygen and hydrogen'. Petro is a five letter prefix meaning 'containing petroleum'. Eka is a three letter prefix meaning 'one less than the normal number of atoms'. Eth is a three letter prefix meaning 'containing ethyl'. Iso is a three letter prefix meaning 'SAME'. Oxa is a three letter prefix meaning 'containing oxygen and carbon'. Tol is a three letter prefix meaning 'containing toluene'. Fluo is a four letter prefix meaning 'containing fluorine'. Phen is a four letter prefix meaning 'containing benzene'. Sila is a four letter prefix meaning 'containing silicon'. Glyco is a five letter prefix meaning 'containing sugar'. Metho is a five letter prefix meaning 'containing methane'. Pheno is a five letter prefix meaning 'containing phenol'. Sodio is a five letter prefix meaning 'containing sodium'. Fluoro is a six letter prefix meaning 'containing fluorine'.