Hidden force floating ice

TL;DR

This paper explains how the unique molecular interactions in water cause ice to be less dense than liquid water, enabling it to float, by analyzing the effects of hydrogen bond disparities and Coulomb repulsion during freezing.

Contribution

It provides a molecular-level explanation of ice's buoyancy based on hydrogen bond and Coulomb interactions, which is a novel insight into water's anomalous properties.

Findings

Cooling elongates the O:H-O bond at freezing.

Ice's lower density is due to bond elongation and angle stretching.

Hydrogen bond disparities cause ice to float.

Abstract

Because of the segmental specific-heat disparity of the hydrogen bond (O:H-O) and the Coulomb repulsion between oxygen ions, cooling elongates the O:H-O bond at freezing by stretching its containing angle and shortening the H-O bond with an association of larger O:H elongation, which makes ice less dense than water, allowing it to float.