Question

which of the lewis structures in the image is correct? a b c d

Explanation:

• For option A: \( PCl_3 \). Phosphorus has 5 valence electrons. In \( PCl_3 \), phosphorus forms 3 single bonds with chlorine atoms. Each chlorine has 7 valence electrons. After bonding, phosphorus has a lone pair (\( 5 - 3= 2 \) electrons as a lone pair), and each chlorine has 3 lone pairs. This structure follows the octet rule (except for the central atom in some cases, but here it's satisfied as \( P \) has \( 3\) bonds + \(1\) lone pair \(= 8\) electrons, and \( Cl\) has \(1\) bond + \(3\) lone pairs \(= 8\) electrons).
• For option B: \( SO_2 \). Sulfur has 6 valence electrons. In a correct Lewis structure of \( SO_2 \), there should be a double - bond (either \( S = O\) or a resonance structure with two \( S - O\) bonds and a lone pair on sulfur). The given structure in B does not account for the double - bond character properly (valence electron count for \( S\) and \( O\) is not satisfied in the given simple single - bond representation).
• For option C: \( H_2C=NaH \). Sodium (\( Na\)) is a metal and forms ionic bonds, not covalent double - bonds as shown in this structure. Carbon forms covalent bonds, but the bonding with \( Na\) in this Lewis structure representation is incorrect (violates the nature of bonding for \( Na\)).
• For option D: \( CBr_2 \). Carbon has 4 valence electrons. In \( CBr_2 \), carbon should form double - bonds with bromine (to satisfy the octet rule as \( C\) needs 8 electrons. With two single bonds, carbon only has \( 4\) electrons from bonds, which is incorrect).

Answer:

A. Option Text