Question

select the lewis structure that most accurately represents chlorine pentafluoride (clf₅). refer to a periodic table.

Explanation:

Step1: Determine valence electrons

Chlorine (Cl) has 7 valence electrons, and each Fluorine (F) has 7 valence electrons. For $\ce{ClF5}$, total valence electrons = $7 + 5\times7 = 7 + 35 = 42$.

Step2: Analyze bonding and lone pairs

Fluorine is a halogen and typically forms a single bond (sharing 2 electrons) and has 3 lone pairs (6 electrons) to complete its octet. Chlorine is the central atom. Each Cl - F bond uses 2 electrons. 5 Cl - F bonds use $5\times2 = 10$ electrons. Remaining electrons on Cl: $42 - 10 - 5\times6$ (lone pairs on F: each F has 6 lone pair electrons, 5 F atoms) $= 42 - 10 - 30 = 2$ (1 lone pair on Cl). So the Lewis structure should have Cl bonded to 5 F atoms (single bonds, since F is highly electronegative and Cl - F single bonds satisfy octet for F, and Cl has one lone pair). Looking at the options, the second structure (top - right) has Cl bonded to 5 F atoms with single bonds, each F has 3 lone pairs, and Cl has one lone pair (2 electrons), which matches the electron count. The other structures have double bonds (which would incorrectly use more electrons or violate F's octet preference, as F rarely forms double bonds due to high electronegativity and small size, preferring single bonds to satisfy octet).

Answer:

The top - right Lewis structure (the second one in the top row) with Cl bonded to 5 F atoms via single bonds, each F having 3 lone pairs, and Cl having one lone pair.