While water has many exceptional and useful properties, which is the rarest property among compounds?

Question

Quizplus · Accepted Answer

Solid water (ice) being less dense than liquid water is the rarest property among compounds. This allows ice to float on water, which is critical for the survival of aquatic life and also helps regulate Earth's climate. Most compounds become denser as they solidify, but the unique crystal structure of water molecules causes ice to have a lower density than liquid water.

While Water Has Many Exceptional and Useful Properties, Which Is