question: How does water from lakes etc. evaporate all the time without having to boil ?
comment: Way way down on the atomic level, the H2O molecules are vibrating and buzzing around, every once in a while, an atom from the "surface" (hard to determine on atomic scale) will vibrate and buzz away from the group, and escape into the atmosphere
passages: An open lake is a lake where water constantly flows out under almost all climatic circumstances. Because water does not remain in an open lake for any length of time, open lakes are usually fresh water: dissolved solids do not accumulate. Open lakes form in areas where precipitation is greater than evaporation. Because most of the world's water is found in areas of highly effective rainfall, most lakes are open lakes whose water eventually reaches the sea. For instance, the Great Lakes' water flows into the St. Lawrence River and eventually the Atlantic Ocean.
   The occurrence of a lake capture is mainly controlled by the water balance at the lake's basin and the changes in topography due to erosion, sedimentation, and tectonism. If evaporation at the surface of a lake, plus the water losses through underground infiltration and plant evapotranspiration are high enough to account for all precipitation water collected by the lake, then the lake becomes endorheic, closed, or internally drained. This situation prevails until the water balance changes again and the lake overburdens the limits of its basin or until the lake capture occurs. Opening the drainage of an endorheic lacustrine basin by fluvial erosion generally implies a lake capture.
   Chemists often use the phrase "standard temperature and pressure" or "STP" to convey that they are working at a temperature of 25 °C and one atmosphere of pressure. There are three states of matter under these conditions: solids, liquids, and gases. Although all three are distinct states, both solids and gases can dissolve (or disperse) in liquids. The most commonly occurring liquid in the biosphere is water. All components of the atmosphere are capable of dissolving in water to some degree. The bulk of the stable natural components of the atmosphere are nitrogen, oxygen, carbon dioxide, gaseous water, argon, and other trace gases. 
   If the amount of water flowing into a lake is less than the amount evaporated, the lake will eventually disappear and leave a dry lake (also called playa or salt flat).
  
  Brine lakes consist of water that has reached salt saturation or near saturation (brine), and may also be heavily saturated with other materials. 
   Gaseous solutes exhibit more complex behavior with temperature. As the temperature is raised, gases usually become less soluble in water (to minimum, which is below 120 °C for most permanent gases), but more soluble in organic solvents.
   A number of chemical reactions have water as a product. If the reactions take place at temperatures higher than the dew point of the surrounding air the water will be formed as vapor and increase the local humidity, if below the dew point local condensation will occur. Typical reactions that result in water formation are the burning of hydrogen or hydrocarbons in air or other oxygen containing gas mixtures, or as a result of reactions with oxidizers.
   The water cycle, also known as the hydrologic cycle or the hydrological cycle, describes the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly constant over time but the partitioning of the water into the major reservoirs of ice, fresh water, saline water and atmospheric water is variable depending on a wide range of climatic variables. The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, condensation, precipitation, infiltration, surface runoff, and subsurface flow. In doing so, the water goes through different forms: liquid, solid (ice) and vapor.
   In flowing systems, differences in solubility often determine the dissolution-precipitation driven transport of species. This happens when different parts of the system experience different conditions. Even slightly different conditions can result in significant effects, given sufficient time.
   Open lakes typically have stable levels which do not fluctuate because input is always matched by outflow to rivers downstream. If more water enters an open lake than was previously leaving it, then more water will leave the lake. The drainage from an open lake, like that from ordinary rivers, is referred to as exorheic (from the Greek "exos", outside and "rhein", to flow).
  
  Section::::Closed lake.
   In the case of evaporation of water to steam, the place occupied by water would be occupied by water vapor, which has a density vastly lower than that of liquid water (the exact number depends on pressure and temperature; at standard conditions, steam is about as dense as liquid water). Because of this lower density (of mass, and consequently of atom nuclei able to absorb neutrons), light water's neutron-absorption capability practically disappears when it boils. This allows more neutrons to fission more U-235 nuclei and thereby increase the reactor power, which leads to higher temperatures that boil even more water, creating a thermal feedback loop.
   Relative to the absolute temperature scale, the excitation levels of the species are gathered based on standard enthalpy change of formation considerations; i.e. their stabilities. As this value is null for water but strictly positive for oxygen and hydrogen, most of the excitation levels of these last species are above the ones of water. Then, the density of the excitation levels for a given temperature range is monotonically increasing with the species entropy. A positive entropy change for water-splitting means far more excitation levels in the products. Consequently,
   Section::::Important abiotic factors.:Chemistry.
   Section::::Important abiotic factors.:Wind.
   Apart from Australia and Southern Africa, it is rare for runoff variability to be high enough for these changes to take place on a useful time scale, and lakes forming in areas where conversions from closed to open or open to closed are likely are very rare. However, Lake Titicaca, the largest lake in South America, has historically been a semi-open lake with very limited outflow, but recent glacial retreat has reduced inflows so much that some believe it could become a completely closed lake in the future. In North Dakota Devils Lake, historically a closed lake, is known to have been an open lake during the Medieval Warm Period. Since 1999, possibly due to global warming, Devils Lake has overflowed into another terminus called Stump Lake, which could overflow into the Red River of the North if present wet conditions in the region continue. Also, the former Tulare Lake in California was known to have overflowed its basin in some years but not others, switching between an open and closed lake.
   It is also possible that the inflow into an open lake could decrease so much that any outflow would dry the lake up completely — that is, the open lake would become a closed lake. The only lake that is currently an open lake for which there is any evidence of a closed lake existing in the same location in the past is Lake Malawi in Africa. It is known that in very dry periods, outflow from the Shire River — Lake Malawi's only outlet — can drop precipitously, and it is strongly believed that during past dry periods outflow from Lake Malawi has ceased entirely and salt has accumulated in the lake, especially during the Last Glacial Maximum and other similarly dry periods.
   Section::::Chemical and physical properties.:Electrical conductivity and electrolysis.
  
  Pure water has a low electrical conductivity, which increases with the dissolution of a small amount of ionic material such as common salt.
  
  Liquid water can be split into the elements hydrogen and oxygen by passing an electric current through it—a process called electrolysis. The decomposition requires more energy input than the heat released by the inverse process (285.8 kJ/mol, or 15.9 MJ/kg).
  
  Section::::Chemical and physical properties.:Mechanical properties.
   The lakes are not fed by streams, and the evaporation rate of the lakes in the hot desert climate exceeds the rate at which rainwater refills them. The lakes are fed by underground water percolating through the rocks and into the lakes. The high evaporation rate produces brackish water in the lakes.
   The stratification in a lake is not always the result of variation to density because of thermal gradients. Stratification within a lake can also be the result of differences in density resulting from gradients in salinity. In case of a difference in salinity, the hypolimnion and epilimnion are separated not by a thermocline but by a halocline, which is sometimes referred to as a "chemocline".
  
  Section::::Other different types of lakes.:Types of lake according to seasonal variation of lake level and volume.
   Since the surface water of deep tropical lakes never reaches the temperature of maximum density, there is no process that makes the water mix. The deeper layer becomes oxygen starved and can become saturated with carbon dioxide, or other gases such as sulfur dioxide if there is even a trace of volcanic activity. Exceptional events, such as earthquakes or landslides, can cause mixing which rapidly brings the deep layers up to the surface and release a vast cloud of gas which lay trapped in solution in the colder water at the bottom of the lake. This is called a limnic eruption. An example is the disaster at Lake Nyos in Cameroon. The amount of gas that can be dissolved in water is directly related to pressure. As deep water surfaces, the pressure drops and a vast amount of gas comes out of solution. Under these circumstances carbon dioxide is hazardous because it is heavier than air and displaces it, so it may flow down a river valley to human settlements and cause mass asphyxiation.
   The sunken Colorado pan is square, 1 m (3 ft) on a side and 0.5 m (18 in.) deep and made of unpainted galvanized iron. As the name suggests, it is buried in the ground to within about 5 cm (2 in.) of its rim. Evaporation from a Sunken Colorado Pan can be compared with a Class A pan using conversion constants. The pan coefficient, on an annual basis, is about 0.8.
  
  Section::::Decreasing Trend of Pan Evaporation.
   In precipitation models this is generally a prelude to models of the growth process itself. Sometimes precipitation is rate-limited by the nucleation process. This happens for example before one takes a cup of superheated water from a microwave and, when jiggling it against dust particles on the wall of the cup, enables "heterogeneous" nucleation that then rapidly converts much of that water into steam.
   The water content of the atmosphere as a whole is constantly depleted by precipitation. At the same time it is constantly replenished by evaporation, most prominently from seas, lakes, rivers, and moist earth. Other sources of atmospheric water include combustion, respiration, volcanic eruptions, the transpiration of plants, and various other biological and geological processes. The mean global content of water vapor in the atmosphere is roughly sufficient to cover the surface of the planet with a layer of liquid water about 25 mm deep. The mean annual precipitation for the planet is about 1 meter, which implies a rapid turnover of water in the air – on average, the residence time of a water molecule in the troposphere is about 9 to 10 days.
   Data in the table above is given for water–steam equilibria at various temperatures over the entire temperature range at which liquid water can exist. Pressure of the equilibrium is given in the second column in kPa. The third column is the heat content of each gram of the liquid phase relative to water at 0 °C. The fourth column is the heat of vaporization of each gram of liquid that changes to vapor. The fifth column is the work "P"Δ"V" done by each gram of liquid that changes to vapor. The sixth column is the density of the vapor.
   BULLET::::- formula_25: most of the particles pass through quickly, but some are held up. This can happen when the main source and sink are very close together or the same. For example, most water vapor rising from the ocean surface soon returns to the ocean, but water vapor that gets sufficiently far away will probably return much later in the form of rain.
  
  Section::::Simple flow models.
  
  Section::::Simple flow models.:Plug flow reactor.
   Section::::Physical properties.:Water, ice, and vapor.:Heat capacity and heats of vaporization and fusion.
  
  Water has a very high specific heat capacity of 4.1814 J/(g·K) at 25 °C – the second highest among all the heteroatomic species (after ammonia), as well as a high heat of vaporization (40.65 kJ/mol or 2257 kJ/kg at the normal boiling point), both of which are a result of the extensive hydrogen bonding between its molecules. These two unusual properties allow water to moderate Earth's climate by buffering large fluctuations in temperature. Most of the additional energy stored in the climate system since 1970 has accumulated in the oceans.
  
presuppositions: Water needs to boil to evaporate.
corrections: Every once in a while, an atom on the surface of the water will escape into the atmosphere without the water needing to boil.
raw_presuppositions: Water needs to boil to evaporate. Water needs to boil to evaporate.
raw_corrections: Every once in a while, an atom on the surface of the water will escape into the atmosphere without the water needing to boil. Every once in a while, an atom on the surface of the water will escape into the atmosphere without the water needing to boil.