Final answer:
The question revolves around identifying plausible Lewis dot structures for CO2, NH3, SO42-, and NO2. All given structures are plausible, following the octet rule and formal charges with CO2 and SO42- having double bonds, NH3 forming single bonds with three hydrogens and a lone pair on nitrogen, and NO2 forming one double and one single bond with oxygen and possessing an unpaired electron on nitrogen.
Step-by-step explanation:
The student is asked to select all plausible Lewis dot structures which are theoretically possible for the given compounds or ions. Lewis dot structures depict the distribution of electrons around atoms. The structures are used to predict the shape and bonding in molecules and ions.
CO2 (Carbon Dioxide): The plausible Lewis structure for CO2 includes two double bonds, one between each oxygen atom and the carbon atom, fulfilling the octet rule for all atoms involved.
NH3 (Ammonia): The plausible Lewis structure for NH3 includes three single bonds between the nitrogen atom and each hydrogen atom, and one lone pair of electrons on the nitrogen, which also fulfills the octet rule for nitrogen.
SO42- (Sulfate Ion): This ion has a plausible Lewis structure with a central sulfur atom double-bonded to four oxygen atoms, and it carries an overall charge of -2 due to two extra electrons.
NO2 (Nitrogen Dioxide): A plausible Lewis structure for NO2 includes one nitrogen atom double-bonded to one oxygen atom and single-bonded to another oxygen atom, with an additional unpaired electron on nitrogen, resulting in a bent molecular geometry.
All the mentioned structures are plausible and adhere to the principles of the octet rule (except NO2 which has an odd number of electrons) and formal charge.