Final answer:
The correct structural formula with the appropriate number of bonds and lone pairs of electrons among the given options is (d) CH₂, which represents a methylene group with two hydrogen atoms bonded to carbon with no lone pairs.
Step-by-step explanation:
The student has asked which structural formula has the correct number of bonds and lone pairs of electrons. We can reject option (a) CHE because it is incomplete and does not represent any known stable molecule. Option (b) CH3 is a correct condensed structural formula for a methyl group, typically part of larger molecules, having three hydrogen atoms bonded to one carbon atom. Option (c) H₂C implies a carbon atom bonded to two hydrogen atoms and is better written as CH2, which indicates a methylene group, often found in hydrocarbons. Finally, (d) CH₂, which is the correct structural formula for a methylene group, has the carbon with two hydrogen bonds and no lone pairs on the carbon.
Furthermore, in the context of Lewis structures and molecular geometry, compounds like CS32- and CS₂ depict different electron density regions and molecular shapes, reinforcing the idea that the representation of molecules must correctly account for the number of bonds and electrons. Similarly, molecules like H3CCH3 and NH3 demonstrate that each atom must have the right number of electrons to form stable compounds.