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What is it called when water vapor escapes from a puddle and goes into the air?
Precipitation
runoff
evaporation
condensation
evaporation
Evaporation is the phase transition of water from a liquid state to a gaseous state (water vapor) occurring at the surface of a liquid body. This process is a fundamental component of the global hydrological cycle, enabling the transfer of moisture from the Earth's surface into the atmosphere.
Evaporation is the phase transition of water from a liquid state to a gaseous state (water vapor) occurring at the surface of a liquid body. This process is a fundamental component of the global hydrological cycle, enabling the transfer of moisture from the Earth's surface into the atmosphere.
E=K⋅f(u)⋅(es−ea) — Dalton's Law of Evaporation where E is evaporation rate, K is a constant, f(u) is wind speed function, es is saturation vapor pressure, and ea is actual vapor pressure.
Q=m⋅Lv — Energy balance required for phase change where Lv≈2.45×10°6 J/kg at 20°C.
Evaporation occurs when water molecules possess sufficient kinetic energy to overcome the intermolecular cohesive forces of the liquid state. This energy is primarily derived from solar radiation (latent heat of vaporization). The rate of evaporation is influenced by factors such as surface temperature, wind velocity, relative humidity, and surface area.
Evaporation occurs at temperatures below the boiling point.
It is a cooling process because the highest-energy molecules escape, reducing the average kinetic energy of the remaining liquid.
The rate is inversely proportional to relative humidity.
Drives the global water cycle.
Acts as a natural cooling mechanism for Earth's surface.
Causes significant water loss in reservoirs and irrigation canals.
Increases salinity in closed water bodies.
Reservoir management and hydrologic modeling.
Design of cooling ponds in power plants.
Salt production from brine evaporation.
Transpiration is the similar process occurring through plant stomata; collectively called Evapotranspiration.
Option A (Precipitation) is water falling from clouds. Option B (Runoff) is the flow of water over land surfaces. Option D (Condensation) is the phase change from gas to liquid.
C is correct — Evaporation is the process where surface liquid molecules gain enough energy to transition into the gaseous phase.
In hydrology problems, always check the vapor pressure deficit (es−ea) as it is the primary driving force for evaporation rates.