paucity (n.) late 14c., from Old French paucitÃ© (14c.) and directly from Latin paucitatem (nominative paucitas) fewness, scarcity, a small number, from paucus few, little, from PIE *pau-ko-, suffixed form of root *pau-(1) few, little (source also of few (adj.)).
All three molecules have four pairs of electrons around their central atom. As a result, they all have a tetrahedral arrangment of electron pairs around the central atom. The bond angle in methane, CH4, is the tetrahedral angle, i.e. 109.5 (109 28'). Ammonia, NH3, contains a lone pair of electrons, which repels the bonding electrons to give a bond angle of 107. The atoms have a trigonal pyramidal arrangement.
Report Abuse. It is trigonal pyramidal, just like ammonia, because its central phosphorous atom is surrounded by three bonding pairs and one lone (non-bonding) pair of electrons...however, the bond angle is now approximately 91 degrees as opposed to the accepted value of 107 degrees for ammonia.ccording to VSEPR theory, the shape of the PH3 molecule is best described as linear. trigonal planar. tetrahedral. bent. trigonal pyramidal. Source(s): vsepr theory shape ph3 molecule as: https://tr.im/v87GF.