The Water Cycle/Hydrologic Cycle

atmosphere

The layer of gas surrounding planet Earth, held in place by gravity and composed primarily of nitrogen and oxygen.

evaporation

Change of a liquid to a vapor or gas.

transpiration

The evaporation of water through openings called stomata in the leaves of plants.

condensation

The change from a gas to a liquid state.

precipitation

Rain, snow, sleet or hail that falls from clouds in the sky.

crystallization

The formation of highly ordered, solid structures from particles in a solution.

gravity

The force of attraction that exists between any two objects

thermal energy

The total kinetic (motion) energy of tiny particles that make up matter. The faster the particles move, the warmer the matter becomes.

hydrosphere

All the water at and near the surface of the earth, 97% of which is in oceans.

solid

A state of matter that has a definite shape and volume.

liquid

A state of matter that has a definite volume but no definite shape.

gas

A state of matter with no definite shape or volume.

water (hydrologic) cycle

The constant movement of water through the land, air, oceans and living things.

percolation/infiltration

The process by which water seeps into the ground.

surface runoff

Rainfall and surface water that drains or flows from the land into streams, rivers, lakes and oceans.

ground water

Water that collects in cracks and pores in underground soil and rock layers.

Earth is the only planet where water exists naturally as a liquid, solid, and gas (water vapor).

Unique characteristic of water.

radiant energy

Energy from the sun that reaches earth as visible light, and ultraviolet and infrared (heat) radiation.

aquifer

A layer of permeable rock that retains and filters water.

accumulation

An increase in amount (of water)over a period of time