CHEMISTRY · Single correct · A Level · Chemistry · Periodicity and periodic trends · Periodicity and periodic trends
Problem
Three potential-energy curves, A, B, and C, are recorded for the diatomic halogens F₂, Cl₂, and Br₂. The positions of their minima are:
• Curve A: 1.41 Å
• Curve B: 1.99 Å
• Curve C: 2.28 Å
Assuming the well depths are similar, which matching of species to curves is most consistent with periodic trends?
(a) A corresponds to Cl₂, B to Br₂, and C to F₂.
(b) A corresponds to Br₂, B to Cl₂, and C to F₂.
(c) A corresponds to F₂, B to Cl₂, and C to Br₂.
(d) A corresponds to Cl₂, B to F₂, and C to Br₂.