Liquid water

Liquid water is H₂O in a fluid state, with a definite volume but no fixed shape. Its hydrogen-bond network continually rearranges, giving it distinctive cohesion, heat capacity, and solvent behavior.

Hydrogen bond: An electrostatic attraction involving hydrogen covalently bonded to an electronegative atom and another electronegative atom. Transient hydrogen bonds connect neighboring water molecules while continually breaking and reforming.
Chemical polarity: Uneven distribution of electrical charge within a molecule or bond. Water’s polarity underlies its attractions to itself and to many dissolved substances.
Aqueous solution: A solution in which water is the solvent. Many substances dissolve or react in water-based mixtures because water is polar.
Ice: The solid crystalline phase of water, commonly formed when liquid water freezes. Ice’s open hydrogen-bonded lattice is less dense than liquid water near freezing.
Thermal inertia of oceans: The tendency of ocean water to resist rapid temperature change because of its large heat capacity and mass. Liquid water stores and redistributes heat, moderating coastal and global climate.
Water molecule: A molecule consisting of two hydrogen atoms bonded to one oxygen atom. Its bent geometry and polar bonds make liquid water’s intermolecular attractions possible.
Phase transition: A change between distinct physical states of matter caused by changes in conditions such as temperature or pressure. Melting and boiling mark the boundaries of liquid water’s stable phase.
Hydration shell: The organized layer of water molecules surrounding a dissolved ion or polar molecule. Water molecules surround solutes, shaping their mobility and interactions in solution.
Water vapor: Water in its gaseous phase, consisting predominantly of dispersed H₂O molecules. Unlike liquid water, vapor has no fixed volume and its molecules are widely separated.
Ocean stratification: The layering of ocean water by density, often driven by temperature and salinity differences. Liquid water’s density changes help organize the ocean into layers that limit mixing.

Linked from 6 pages