Answer: Cl 2 has optimal overlap of 3p-3p; F-F has lone pair repulsion; Br and I have weaker, more diffuse overlap.
- A Cl<sub>2</sub> has optimal overlap of 3p-3p; F-F has lone pair repulsion; Br and I have weaker, more diffuse overlap
- B Chlorine generally carries the highest electronegativity among all four halogens in typical laboratory settings
- C Fluorine's extreme chemical reactivity is what directly sets the bond energy order under usual circumstances
- D Iodine's much larger atomic size alone is what largely explains the entire trend according to most researchers
Correct answer: A. Cl<sub>2</sub> has optimal overlap of 3p-3p; F-F has lone pair repulsion; Br and I have weaker, more diffuse overlap
Explanation: F-F is weakened by lone pair repulsion in tiny F atoms; Br and I have larger, more diffuse orbitals with poorer overlap; Cl<sub>2</sub> hits the sweet spot.
VSEPR theory predicts molecular shape from the number of bonding and lone electron pairs around the central atom.
Concept context
Understand how atoms join to form molecules. Covers ionic and covalent bonding, VSEPR theory, hybridization (sp, sp², sp³), molecular orbital theory, bond polarity, and intermolecular forces like hydrogen bonding.
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