Home / Science

Science of Water

The molecular foundation of life and the most studied substance on Earth.

Water (H₂O) is a simple molecule with extraordinary properties. It is the only substance that exists naturally in all three states of matter on Earth’s surface — solid, liquid, and gas.

FUNDAMENTALS

Molecular Structure

Water consists of two hydrogen atoms covalently bonded to one oxygen atom. The molecule has a bent shape with a bond angle of 104.5°.

Key Properties
  • Polar molecule — excellent solvent
  • High specific heat capacity
  • High surface tension
  • Expands when freezing (density anomaly)
H2O
The universal solvent
THE ENGINE OF LIFE

The Water Cycle

A continuous global process that moves water between the atmosphere, land, and oceans.

Evaporation
Water turns into vapor from oceans, lakes, and land surfaces due to solar energy.
Condensation
Water vapor cools and condenses into clouds in the atmosphere.
Precipitation
Water falls back to Earth as rain, snow, sleet, or hail.
Collection
Water collects in rivers, lakes, oceans, and groundwater aquifers.
Transpiration
Plants release water vapor into the atmosphere through their leaves.

Key Topics in Water Science

States of Matter

Ice (solid), water (liquid), and steam (gas) — and the unique behavior of water when it freezes.

pH and Chemistry

Water’s role as a universal solvent and its slightly acidic or basic nature depending on dissolved substances.

Hydrogen Bonding

The weak bonds between water molecules responsible for its high boiling point and surface tension.