JAMB Chemistry 2019 Paper

Concept:Molecular shapes are determined by the arrangement of electron pairs around the central atom (VSEPR theory).Explanation:Water is $\mathrm{H_2O}$ and has a bent or angular shape because of two lone pairs on oxygen.Ammonia is $\mathrm{NH_3}$ and has a trigonal pyramidal shape due to one lone pair on nitrogen.Carbon(IV) oxide is $\mathrm{CO_2}$ and is a linear molecule because it has no lone pairs on the central carbon atom.Methane is $\mathrm{CH_4}$ and has a regular tetrahedral shape.So, their shapes are: angular, pyramidal, linear, and tetrahedral respectively.Answer:B. angular, pyramidal, linear and tetrahedral.