Water vapor
Systematic name	Water Vapor
Liquid State	Water
Solid state	Ice
Properties[1]
Melting point	0 °C
Boiling point	100 °C
individual gas constant	461. There are millions of possible objects that can be described in science too many to create Common names for every one Liquid is one of the principal States of matter. A liquid is a Fluid that has the particles loose and can freely form a distinct surface at the boundaries of A solid' object is in the States of matter characterized by resistance to Deformation and changes of Volume. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid 5 J/(kg·K)
latent heat of evaporation	2. 27 MJ/kg
molecular weight	18. The molecular mass (abbreviated m of a substance, more commonly referred to as molecular weight and abbreviated as MW, is the Mass of one 02 g/mol
specific heat capacity	1. Specific heat capacity, also known simply as specific heat, is the measure of the heat energy required to increase the Temperature of a unit quantity 84 kJ/(kg·K)

Water vapor or water vapour (see spelling differences), also aqueous vapor, is the gas phase of water. American and British English spelling differences are one aspect of American and British English differences. This page is about the physical properties of gas as a state of matter Water ( H2[[oxygen O]] H OH) is the most abundant Molecule on Earth 's surface composing of about 70% of the Earth's surface as Water vapor is one state of the water cycle within the hydrosphere. A vapor or vapour (see Spelling differences) is a substance in the Gas phase at a Temperature lower than its Critical temperature In the Physical sciences a phase is a Set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties The Earth 's Water is always in movement and the water cycle, also known as the hydrologic cycle, describes the continuous movement of water on above A hydrosphere (from Greek ύδωρ - hydor, " Water " + σφαίρα - sphaira, " Sphere " ^[2] Water vapor can be produced from the evaporation of liquid water or from the sublimation of ice. Evaporation is the process by which Molecules in a Liquid state (e Water is a common Chemical substance that is essential for the survival of all known forms of Life. Sublimation of an element or compound is a transition from the Solid to Gas phase with no intermediate liquid stage Ice is a Solid phase, usually crystalline, of a Non-metalic substance that is liquid or gas at Room temperature, such as Ammonia Under normal atmospheric conditions,^[3] water vapor is continuously generated by evaporation and removed by condensation. Condensation is the change of the physical state of aggregation (or simply state of matter from gaseous phase into liquid phase

Contents 1 General properties of water vapor 1.1 Evaporation/sublimation 1.2 Condensation 1.3 Water vapor density 1.3.1 Water vapor and dry air density calculations at 0°C 1.3.2 Air and water vapor density interactions at equal temperatures 1.4 Water vapour and respiration or breathing 1.5 General discussion 2 Water vapor in Earth's atmosphere 2.1 Radar and satellite imaging 2.2 Lightning generation 2.3 Extraterrestrial water vapor 3 Scientific Discrepancies, Confounding factors and limits of knowledge 4 See also 5 External links 6 Footnotes/References

General properties of water vapor

Evaporation/sublimation

Whenever a water molecule leaves a surface, it is said to have evaporated. Each individual water molecule which transitions between a more associated (liquid) and a less associated (vapor/gas) state does so through the absorption or release of kinetic energy. The aggregate measurement of this kinetic energy transfer is defined as thermal energy and occurs only when there is differential in the temperature of the water molecules. Liquid water that becomes water vapor takes a parcel of heat with it, in a process called evaporative cooling. In Physics, heat, symbolized by Q, is Energy transferred from one body or system to another due to a difference in Temperature Evaporative coolers (also called swamp, desert, or air coolers) are devices that cool air through the simple Evaporation of water ^[4] The amount of water vapor in the air determines how fast each molecule will return back to the surface. When a net evaporation occurs, the body of water will undergo a net cooling directly related to the loss of water. ^[5]

In the US, the National Weather Service measures the actual rate of evaporation from a standardized "pan" open water surface outdoors, at various locations nationwide. Others do likewise around the world. The US data is collected and compiled into an annual evaporation map. [1] The measurements range from under 30 to over 120 inches per year. Formulas for calculating the rate of evaporation from a water surface such as a swimming pool of can be found here[2] and here[3]

Evaporative cooling is restricted by atmospheric conditions. In Physical sciences standard conditions for temperature and pressure are Standard sets of conditions for experimental measurements to allow comparisons to be made Humidity is the amount of water vapor in the air. Humidity is the amount of water vapor in the air In daily language the term "humidity" is normally taken to mean Relative humidity. The vapor content of air is measured with devices known as hygrometers. Hygrometers are instruments used for measuring Humidity. A simple form of a hygrometer is specifically known as a "psychrometer" and consists of two Thermometers The measurements are usually expressed as specific humidity or percent relative humidity. Humidity is the amount of water vapor in the air In daily language the term "humidity" is normally taken to mean Relative humidity. Relative humidity is a measurement of the amount of Water vapor that exists in a gaseous mixture of air and water The temperatures of the atmosphere and the water surface determine the equilibrium vapor pressure; 100% relative humidity occurs when the partial pressure of water vapor is equal to the equilibrium vapor pressure. This condition is often referred to as complete saturation. Humidity ranges from 0 gram per cubic metre in dry air to 30 grams per cubic metre (0. 03 ounce per cubic foot) when the vapour is saturated at 30 °C. [4] (See also Absolute Humidity table)

Another form of evaporation is sublimation, by which water molecules become gaseous directly from ice without first becoming liquid water. Sublimation of an element or compound is a transition from the Solid to Gas phase with no intermediate liquid stage Sublimation accounts for the slow mid-winter disappearance of ice and snow at temperatures too low to cause melting.

Condensation

Water vapor will only condense onto another surface when that surface is cooler than the temperature of the water vapor, or when the water vapor equilibrium in air has been exceeded. Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium When water vapor condenses onto a surface, a net warming occurs on that surface. ^[6] The water molecule brings a parcel of heat with it. In turn, the temperature of the atmosphere drops slightly. ^{[7] [8]} In the atmosphere, condensation produces clouds, fog and precipitation (usually only when facilitated by cloud condensation nuclei). Cloud condensation nuclei or CCN s (also known as cloud seeds) are small particles (typically 0 The dew point of an air parcel is the temperature to which it must cool before water vapor in the air begins to condense. The dew point (sometimes spelled dewpoint) is the Temperature to which a given parcel of Air must be cooled at constant Barometric pressure,

Also, a net condensation of water vapor occurs on surfaces when the temperature of the surface is at or below the dew point temperature of the atmosphere. Deposition, the direct formation of ice from water vapor, is a type of condensation. Frost and snow are examples of deposition. Frost is the solid deposition of Water vapor from saturated air "Snowfall" redirects here For other uses see Snow (disambiguation or Snowfall (disambiguation. Deposition is a process in which gas transforms into solid (also known as desublimation

Water vapor density

Water vapor is lighter or less dense than dry air. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different At equivalent temperatures it is buoyant with respect to dry air.

Water vapor and dry air density calculations at 0°C

The molecular mass or weight of water is 18. The molecular mass (abbreviated m of a substance, more commonly referred to as molecular weight and abbreviated as MW, is the Mass of one 02g/mol, as calculated from the sum of the atomic masses of its constituent atoms. The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny

The average molecular mass of air (Approx. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five 79% nitrogen, N₂; 21% Oxygen, 0₂) is 28. 57g/mol at standard temperature and pressure (STP). In Physical sciences standard conditions for temperature and pressure are Standard sets of conditions for experimental measurements to allow comparisons to be made

Using Avogadro's Law and the ideal gas law, water vapor and air will have a molar volume of 22. Avogadro's law ( Avogadro's Hypothesis, or Avogadro's Principle) is a Gas law named after Amedeo Avogadro, who in 1811 hypothesized These four properties that constitute an ideal gas can be easily remembered by the acronym RIPE which stands for - R andom Motion (molecules are in constant random motion The molar volume, symbol V m is the Volume occupied by one mole of a substance ( Chemical element or Chemical compound) 414 litre/mol at STP. A molar mass of air and water vapour occupy the same volume of 22. 414 litres. The density (mass/volume) of water vapor is 0. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 804g/litre, which is significantly less than that of dry air at 1. 27g/litre at STP.

Note that STP conditions include a temperature of 0°C, at which the ability of water to become vapor is very restricted. Its concentration in air is very low at 0°C. In Chemistry, concentration is the measure of how much of a given substance there is mixed with another substance The red line on the chart to the right is the maximum concentration of water vapor expected for a given temperature. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature The water vapor concentration increases significantly as the temperature rises, approaching 100% (steam, pure water vapor) at 100°C. Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. However the difference in densities between air and water vapour would still exist.

Air and water vapor density interactions at equal temperatures

At the same temperature, a column of dry air will be denser or heavier than a column of air containing any water vapor. Thus, any volume of dry air will sink if placed in a larger volume of moist air. Also, a volume of moist air will rise or be buoyant if placed in a larger region of dry air. In Physics, buoyancy ( BrE IPA: /ˈbɔɪənsi/ is the upward Force on an object produced by the surrounding liquid or gas in which it is As the temperature rises the proportion water vapor in the air increases, its buoyancy will become larger. This increase in buoyancy can have a signicant atmospheric impact, giving rise to powerful, moisture rich, upward air currents when the air temperature and sea temperature reaches 25°C or above. This phenomenon provides a significant motivating force for cyclonic and anticyclonic weather systems (tornados and hurricanes). In Meteorology, a cyclone refers to an area of closed circular fluid motion rotating in the same direction as the Earth.

Water vapour and respiration or breathing

Water vapor's contribution to the pressure increases as its concentration increases. Its partial pressure contribution to air pressure increases, lowering the partial pressure contribution of the other atmospheric gases (Dalton's Law). In a mixture of Ideal gases each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume In a mixture of Ideal gases each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume The total air pressure must remain constant. The presence of water vapor in the air naturally dilutes or displaces the other air components as its concentration increases.

This can have an effect on respiration, in very warm air (35°C). The proportion of water vapor is significant enough to give rise to the stuffiness that can be experienced in humid jungle conditions or in poorly air conditioned buildings.

General discussion

The amount of water vapor in an atmosphere is constrained by the restrictions of partial pressures and temperature. Dew point temperature and relative humidity act as guidelines for the process of water vapor in the water cycle. Energy input, such as sunlight, can trigger more evaporation on an ocean surface or more sublimation on a chunk of ice on top of a mountain. The balance between condensation and evaporation gives the quantity called vapor partial pressure^[9]. Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium

The maximum partial pressure (saturation pressure) of water vapor in air varies with temperature of the air and water vapor mixture. A variety of empirical formulas exist for this quantity; the most used reference formula is the Goff-Gratch equation for the SVP over liquid water:

Where T, temperature of the moist air, is given in units of kelvins, and p is given in units of millibars (hectopascals). The Goff-Gratch equation is one (arguably the first reliable amongst many equations that have been proposed to estimate the saturation water vapor pressure at a given temperature The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The bar (symbol bar) decibar (symbol dbar) and the millibar (symbol mbar, also mb are units of Pressure.

The formula is valid from about −50 to 102 °C; however there are a very limited number of measurements of the vapor pressure of water over supercooled liquid water. ^[10]

Under adverse conditions, such as when the boiling temperature of water is reached, a net evaporation will always occur during standard atmospheric conditions regardless of the percent of relative humidity. This immediate process will dispel massive amounts of water vapor into a cooler atmosphere.

Exhaled air is almost fully at equilibrium with water vapor at the body temperature. In the cold air the exhaled vapor quickly condenses, thus showing up as a fog or mist of water droplets and as condensation or frost on surfaces. Mist is a phenomenon of small droplets suspended in Air. It can occur as part of natural Weather or Volcanic activity and is common in cold air above

Controlling water vapor in air is a key concern in the heating, ventilating, and air-conditioning (HVAC) industry. HVAC (pronounced either "H-V-A-C" or occasionally " H-vak " is an Initialism or Acronym that stands for " Heating Thermal comfort depends on the moist air conditions. Human thermal comfort is defined by ASHRAE as the state of mind that expresses satisfaction with the surrounding environment (ASHRAE Standard 55 Non-human comfort situations are called refrigeration, and also are affected by water vapor. Refrigeration is the process of removing Heat from an enclosed space or from a substance and moving it to a place where it is unobjectionable For example many food stores, like supermarkets, utilize open chiller cabinets, or food cases, which can significantly lower the water vapor pressure (lowering humidity). This practice delivers several benefits as well as problems.

Water vapor in Earth's atmosphere

Gaseous water represents a small but environmentally significant constituent of the atmosphere. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Approximately 99. 99% of it is contained in the troposphere. The troposphere is the lowest portion of Earth's atmosphere. It contains approximately 75% of the atmosphere's mass and almost all of its Water vapor and The condensation of water vapor to the liquid or ice phase is responsible for clouds, rain, snow, and other precipitation, all of which count among the most significant elements of what we experience as weather. Condensation is the change of the physical state of aggregation (or simply state of matter from gaseous phase into liquid phase A cloud is a visible mass of droplets or frozen crystals floating in the atmosphere above the surface of the Earth or another Planetary body Rain is Liquid precipitation. On Earth it is the condensation of atmospheric Water vapor into drops heavy enough to fall often making it to "Snowfall" redirects here For other uses see Snow (disambiguation or Snowfall (disambiguation. The weather is a set of all the phenomena occurring in a given Atmosphere at a given Time. Less obviously, the latent heat of vaporization, which is released to the atmosphere whenever condensation occurs, is one of the most important terms in the atmospheric energy budget on both local and global scales. The enthalpy of vaporization, (symbol \Delta{}_{v}H also known as the heat of vaporization or heat of evaporation, is the Energy required For example, latent heat release in atmospheric convection is directly responsible for powering destructive storms such as tropical cyclones and severe thunderstorms. Convection in the most general terms refers to the movement of molecules within Fluids (i A tropical cyclone is a storm system characterized by a low pressure center and numerous Thunderstorms that produce strong winds and Flooding Water vapor is also a potent greenhouse gas. Greenhouse gases are gaseous constituents of the atmosphere bothnatural and anthropogenic that absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared Because the water vapor content of the atmosphere is expected to greatly increase in response to warmer temperatures, there is the potential for a water vapor feedback that could amplify the expected climate warming effect due to increased carbon dioxide alone. Greenhouse gases are gaseous constituents of the atmosphere bothnatural and anthropogenic that absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single However, it is less clear how cloudiness would respond to a warming climate; depending on the nature of the response, clouds could either further amplify or partly mitigate the water vapor feedback.

Fog and clouds form through condensation around cloud condensation nuclei. Fog is a cloud that is in contact with the ground Stratus clouds are usually the only clouds that touch the ground Cloud condensation nuclei or CCN s (also known as cloud seeds) are small particles (typically 0 In the absence of nuclei, condensation will only occur at much lower temperatures. Under persistent condensation or deposition, cloud droplets or snowflakes form, which precipitate when they reach a critical mass. In Meteorology, precipitation (also known as one class of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric

The average residence time of water molecules in the troposphere is about 10 days. The troposphere is the lowest portion of Earth's atmosphere. It contains approximately 75% of the atmosphere's mass and almost all of its Water vapor and Water depleted by precipitation is replenished by evaporation from the seas, lakes, rivers and the transpiration of plants, and other biological and geological processes.

Measurements of vapor concentration are expressed as specific humidity or percent relative humidity. Humidity is the amount of water vapor in the air In daily language the term "humidity" is normally taken to mean Relative humidity. Relative humidity is a measurement of the amount of Water vapor that exists in a gaseous mixture of air and water The annual mean global concentration of water vapor would yield about 25 mm of liquid water over the entire surface of the Earth if it were to instantly condense. However, the mean annual precipitation for the planet is about 1 meter, which indicates a rapid turnover of water in the air.

The abundance of gases emitted by volcanoes varies considerably from volcano to volcano. Plate tectonics and hotspots Divergent plate boundaries At the However, water vapor is consistently the most common volcanic gas, normally comprising more than 60% of total emissions during a subaerial volcanic eruption. Volcanic gases include a variety of substances given off by active (or at times by dormant Volcanoes These include gases trapped in cavities ( Vesicles) in ^[11]

Radar and satellite imaging

Because water molecules absorb microwaves and other radio wave frequencies, water in the atmosphere attenuates radar signals. MODIS ( Moderate-resolution Imaging Spectroradiometer) is a payload scientific instrument launched into Earth orbit by NASA in 1999 on board In Physics, absorption of electromagnetic radiation is the process by which the Energy of a Photon is taken up by matter typically the electrons of an Microwaves are electromagnetic waves with Wavelengths ranging from 1 mm to 1 m or frequencies between 0 Radio waves are electromagnetic waves occurring on the Radio frequency portion of the Electromagnetic spectrum. Radar is a system that uses electromagnetic waves to identify the range altitude direction or speed of both moving and fixed objects such as Aircraft, ships ^[12] In addition, atmospheric water will reflect and refract signals to an extent that depends on whether it is vapor, liquid or solid. Reflection is the change in direction of a Wave front at an interface between two different media so that the wave front returns into the medium from which Refraction is the change in direction of a Wave due to a change in its Speed. ^[13]

Generally, radar signals lose strength progressively the farther they travel through the troposphere. Different frequencies attenuate at different rates, such that some components of air are opaque to some frequencies and transparent to others. Radio waves used for broadcasting and other communication experience the same effect.

Water vapor reflects radar^[14] to a less extent than do water's other two phases. In the form of drops and ice crystals, water acts as a prism, which it does not do as an individual molecule; however, the existence of water vapor in the atmosphere causes the atmosphere to act as a giant prism. In Chemistry, a molecule is defined as a sufficiently stable electrically neutral group of at least two Atoms in a definite arrangement held together by ^[15]

A comparison of GOES-12 satellite images shows the distribution of atmospheric water vapor relative to the oceans, clouds and continents of the Earth. These two images for this satellite image comparisons come from the GOES12 Satellite. Vapor surrounds the planet but is unevenly distributed.

Lightning generation

Water vapor plays a key role in lightning production in the atmosphere. Lightning is an atmospheric discharge of Electricity, which typically occurs during Thunderstorms and sometimes during volcanic eruptions or From cloud physics, usually, clouds are the real generators of static charge as found in Earth's atmosphere. Cloud physics is the study of the physical processes that lead to the formation growth and precipitation of Clouds Clouds are composed of Microscopic droplets Electric charge is a fundamental conserved property of some Subatomic particles which determines their Electromagnetic interaction. But the ability, or caterbility of clouds to hold massive amounts of electrical energy is directly related to the amount of water vapor present in the local system.

The amount of water vapor directly controls the permittivity of the air. Permittivity is a Physical quantity that describes how an Electric field affects and is affected by a Dielectric medium and is determined by the ability During times of low humidity, static discharge is quick and easy. During times of higher humidity, fewer static discharges occur. However, permittivity and capacitance^[16] work hand in hand to produce the megawatt outputs of lightning.

After a cloud, for instance, has started its way to becoming a lightning generator, atmospheric water vapor acts as a substance (or insulator^{[17] [18]} ) that decreases the ability of the cloud to discharge its electrical energy. An insulator, also called a Dielectric, is a material that resists the flow of Electric current. Electrostatic discharge ( ESD) is the sudden and momentary Electric current that flows between two objects at different Electrical potentials The term is Over a certain amount of time, if the cloud continues to generate and store^[19] more static electricity^[20], the barrier that was created by the atmospheric water vapor will ultimately break down^[21] from the stored electrical potential energy. For the science of static charges see Electrostatics Static electricity refers to the accumulation of excess Electric charge in a This energy will be released to a locally, opposite^[22] charged region in the form of lightning. The strength of each discharge is directly related to the atmospheric permittivity, capacitance, and the source's charge generating ability. ^[23]

See also, Van de Graaff generator. A Van de Graaff generator is an electrostatic machine which uses a moving belt to accumulate very high electrostatically stable Voltages on a hollow metal globe

Extraterrestrial water vapor

The brilliance of comet tails comes largely from water vapor. On approach to the sun, the ice many comets carry sublimates to vapor, which reflects light from the sun. The Sun (Sol is the Star at the center of the Solar System. A comet is a small Solar System body that orbits the Sun and when close enough to the Sun exhibits a visible coma (atmosphere or a tail — Sublimation of an element or compound is a transition from the Solid to Gas phase with no intermediate liquid stage Knowing a comet's distance from the sun, astronomers may deduce a comet's water content from its brilliance. ^[24] Bright tails in cold and distant comets suggests carbon monoxide sublimation.

Scientists studying Mars hypothesize that if water moves about the planet, it does so as vapor. ^[25] Most of the water on Mars appears to exist as ice at the northern pole. During Mars' summer, this ice sublimates, perhaps enabling massive seasonal storms to convey significant amounts of water toward the equator. ^[26]

A star called CW Leonis was found to have a ring of vast quantities of water vapor circling the aging, massive star. A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth A NASA satellite designed to study chemicals in interstellar gas clouds, made the discovery with an onboard spectrometer. The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program Most likely, "the water vapor was vaporized from the surfaces of orbiting comets. "^[27]

Spectroscopic analysis of HD 209458 b, an extrasolar planet in the constellation Pegasus, provides the first evidence of atmospheric water vapor beyond the Solar System. HD 209458 b, also unofficially named Osiris, is an Extrasolar planet that orbits the Solar twin Star HD 209458 in the constellation

Scientific Discrepancies, Confounding factors and limits of knowledge

Since water vapor is very common, it has been studied and written about from many perspectives. As working knowledge has grown and developed within apparently unrelated fields several discrepancies in understanding may be encountered. These discrepancies often arise from an inability to rigidly determine either a volumetric or gravimetric basis of study; and/or use of constants inappropriate for the conditions being observed.

Many scientific studies view water vapor as a Confounding variable (preventing Ceteris paribus, also 'lurking variable') due to its complex nature; this becomes especially true when the study observes significant variation in water vapor quantities, over time and/or location. In statistics a confounding variable (also confounding factor, lurking variable, a confound, or confounder) is an Extraneous variable la Cēterīs paribus is a Latin phrase literally translated as "with other things the same

It is for the reasons above that this remains a particularly tricky and sometimes controversial factor in many fields of science, whether storage of foods or ancient artefacts, thermodynamics or climate change.

See also

air boiling point Condensation in aerosol dynamics deposition equation of state Evaporative cooler fog frost gas laws Gibbs free energy

Gibbs phase rule greenhouse gas heat capacity heat of vaporization ideal gas kinetic theory of gases latent heat flux latent heat

microwave radiometer phase of matter steam superheating supersaturation thermodynamics troposphere vapor pressure

External links

• National Science Digital Library - Water Vapor
• Measuring Water Vapor : A lesson plan from the National Science Digital Library. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid Condensation can be summarized as a phase transition from a gas to a liquid as vapor condenses on a pre-existing surface the exact opposite of the transition from liquid Deposition is a process in which gas transforms into solid (also known as desublimation In Physics and Thermodynamics, an equation of state is a relation between state variables More specifically an equation of state is a thermodynamic Evaporative coolers (also called swamp, desert, or air coolers) are devices that cool air through the simple Evaporation of water Fog is a cloud that is in contact with the ground Stratus clouds are usually the only clouds that touch the ground Frost is the solid deposition of Water vapor from saturated air This articles outlines the historical development of the laws describing ideal gases In Thermodynamics, the Gibbs free energy ( IUPAC recommended name Gibbs energy or Gibbs function) is a Thermodynamic potential which Gibbs' phase rule, stated by Josiah Willard Gibbs in the 1870s is the fundamental rule on which Phase diagrams are based Greenhouse gases are gaseous constituents of the atmosphere bothnatural and anthropogenic that absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared Specific heat capacity, also known simply as specific heat, is the measure of the heat energy required to increase the Temperature of a unit quantity The enthalpy of vaporization, (symbol \Delta{}_{v}H also known as the heat of vaporization or heat of evaporation, is the Energy required These four properties that constitute an ideal gas can be easily remembered by the acronym RIPE which stands for - R andom Motion (molecules are in constant random motion Kinetic theory (or kinetic theory of gases) attempts to explain Macroscopic properties of Gases such as pressure temperature or volume by considering Latent heat flux is the flux of heat from the Earth's surface to the atmosphere that is associated with Evaporation of water at the surface and subsequent Condensation In Thermochemistry, latent heat is the amount of Energy in the form of Heat released or absorbed by a substance during a change of phase A Microwave Radiometer (MWR is a Radiometer that measures energy emitted at sub-millimetre-to-centimetre wavelengths (at frequencies of 1-1000 GHz) known as In the Physical sciences a phase is a Set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. See Superheater for the device used in Steam engines In Physics, superheating (sometimes referred to as boiling retardation The term supersaturation refers to a Solution that contains more of the dissolved material than could be dissolved by the Solvent under normal circumstances In Physics, thermodynamics (from the Greek θερμη therme meaning " Heat " and δυναμις dynamis meaning " The troposphere is the lowest portion of Earth's atmosphere. It contains approximately 75% of the atmosphere's mass and almost all of its Water vapor and Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium
• psu.edu science misconceptions - Bad Clouds
• Calculate the condensation of your exhaled breath
• Water Vapor Myths: A Brief Tutorial
• AGU Water Vapor in the Climate System - 1995

Footnotes/References

© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic