Experimental data show that the two O–O bonds in O₃ are identical in length and strength. Which statement best justifies depicting O₃ with resonance structures?
a) Because the molecule rapidly oscillates between a single-bonded and a double-bonded form, the two bonds are observed to have the same length.
b) Equivalent bond lengths indicate that the π electrons are delocalized over both O–O bonds.
c) Equal bond lengths show that the σ electrons are shared equally between both O–O bonds.
d) Resonance structures are needed since no single drawing allows every oxygen atom to satisfy the octet rule without exceeding it.