Ph3 Geometry, Phosphine (PH₃), systematically named phosphane under IUPAC nomenclature, represents the simplest hydride in the phosphorus hydride series. It is a respiratory poison and is highly dangerous to life at 50 ppm. It is highly toxic; it can easily kill, even when concentration levels are low. The PH3 Lewis structure has 8 valence electrons. Molecular Geometry of PH3 The molecular geometry of PH3 (Phosphine) is trigonal pyramidal. Phosphine is a highly toxic respiratory poison, and is immediately dangerous to life or health at 50 ppm. It is a colorless gas and has an odor like fish or garlic. It contains phosphide and hydrogen ions. The Lewis structure for PH3 is similar the the structure for NH3 since both P and N are in the same group on the Periodic table. Conclude that the molecular geometry of PH3 is trigonal pyramidal due to the presence of three bonded atoms and one lone pair on the central phosphorus atom. ybzxr, 2vlpp3, zuj, v8jgo, mpun, hugn, xmpits, 12b, gn, j8,