Supercooled water, the hydrated proton and electron

Water behaves unlike most liquids: it is densest at 4 C and its compressibility and heat capacity grow sharply as it is cooled below freezing without crystallizing. How an extra proton or an extra electron is arranged in water, and how protons move through it so fast, is also only partly understood.

Why it matters

Water is the medium of most chemistry and all biology, and its anomalies, proton transport and radiation chemistry enter climate, electrochemistry and enzyme function.

Review

P. Gallo et al., Water: A Tale of Two Liquids, Chemical Reviews, 2016. https://doi.org/10.1021/acs.chemrev.5b00750 reference checked

Timestamp record

Signed record
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Public log
Entry 109, in checkpoint 2,123
In the log by
Block 969,698, 2026-10-03

This text was in the PubPhys log by that date. The date says nothing about when the problem was first posed.

4 problems