observe that some materials change state when they are heated or cooled, and measure or research the temperature at which this happens in degrees Celsius (°C) The Matki/Matka, a traditional Indian porous clay container used for storing and cooling water and other liquids. There is a limit to how much water vapour the atmosphere can hold. This limit is proportional to the temperature (which implies that hot air can hold more water vapour than cold air). Evaporation can be viewed as an equilibrium process through which the amount of water vapour in the atmosphere reaches an equilibrium with the amount of water in the surface of the liquid. Therefore, the greater the amount of water vapour in the atmosphere over the liquid, the slower the rate of evaporation. Also, it can be noted that an increase in temperature with constant humidity will contribute to an increase in the rate of evaporation since hot air can hold a greater amount of water vapour. Air Circulation or Wind Speed

Evaporation is an essential part of the water cycle. The sun (solar energy) drives evaporation of water from oceans, lakes, moisture in the soil, and other sources of water. In hydrology, evaporation and transpiration (which involves evaporation within plant stomata) are collectively termed evapotranspiration. Evaporation of water occurs when the surface of the liquid is exposed, allowing molecules to escape and form water vapor; this vapor can then rise up and form clouds. With sufficient energy, the liquid will turn into vapor. The easy-to-print sheets all feature a clear and straightforward layout that makes it easy to break down and plan out the experiment from initial hypotheses to recording the results, giving children a wonderful insight into beginning to use structured experiments to test scientific theories. Experiments are a particularly good way to introduce children to new topics in science since they give children a hands-on way to see the theory in action that's both the best way to help them see how the laws of science apply to the world around them and fun activity that they're sure to enjoy! More science investigation resources Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. [1] High concentration of the evaporating substance in the surrounding gas significantly slows down evaporation, such as when humidity affects rate of evaporation of water. [2] When the molecules of the liquid collide, they transfer energy to each other based on how they collide. When a molecule near the surface absorbs enough energy to overcome the vapor pressure, it will escape and enter the surrounding air as a gas. [3] When evaporation occurs, the energy removed from the vaporized liquid will reduce the temperature of the liquid, resulting in evaporative cooling. [4] After a couple of days, the solution I left on the windowsill has also evaporated. The energy from the sun has warmed the solution, speeding up evaporation. Like before, the water has turned into gas in the air and the salt has been left behind. Note! The units for Θ don't match since the this is an empirical equation - a result of experience and experiments. Required Heat Supplyx s = maximum humidity ratio of saturated air at the same temperature as the water surface (kg/kg) (kg H 2 O in kg Dry Air) The ability for a molecule of a liquid to evaporate is based largely on the amount of kinetic energy an individual particle may possess. Even at lower temperatures, individual molecules of a liquid can evaporate if they have more than the minimum amount of kinetic energy required for vaporization. The botijo, a traditional Spanish porous clay container designed to cool the contained water by evaporation. ln ⁡ ( P 2 P 1 ) = − Δ H v a p R ( 1 T 2 − 1 T 1 ) {\displaystyle \ln \left({\frac {P_{2}}{P_{1}}}\right)=-{\frac {\Delta H_{\rm {vap}}}{R}}\left({\frac {1}{T_{2}}}-{\frac {1}{T_{1}}}\right)}

Before long, the water level drops. Even after we take the heat away, the liquid continues to evaporate, leaving crystals of salt behind. Note: Air is used here as a common example of the surrounding gas; however, other gases may hold that role. The Mollier diagram is a graphic representation of the relationship between air temperature, moisture content and enthalpy - and is a basic design tool for building engineers and designers. On average, only a fraction of the molecules in a liquid have enough heat energy to escape from the liquid. The evaporation will continue until an equilibrium is reached when the evaporation of the liquid is equal to its condensation. In an enclosed environment, a liquid will evaporate until the surrounding air is saturated. Evaporation happens when a liquid turns into a gas. It can be easily visualized when rain puddles “disappear” on a hot day or when wet clothes dry in the sun. In these examples, the liquid water is not actually vanishing—it is evaporating into a gas, called water vapor.Evaporation is a process by which a substance changes from a liquid state to a gaseous state at temperatures below the boiling point of the liquid. In nature, evaporation—especially from the oceans—plays a key role in the water cycle by moving water from its liquid state on Earth’s surface to the atmosphere as water vapor. The rate of evaporation depends on the temperature difference between the surface of the liquid and the air. The greater the difference in temperature, the faster evaporation occurs. How Evaporation Occurs

There are two key differences between evaporation and boiling. The first difference is where the change of state occurs. Evaporation takes place only at the surface of a liquid, whereas boiling may occur throughout the liquid. In boiling, the change of state takes place at any point in the liquid where bubbles form; the bubbles then rise and break at the surface of the liquid. The second difference between evaporation and boiling concerns temperature. Evaporation can take place at any temperature. For example, a puddle of water will evaporate on a cold day, though the rate of evaporation will be slower than it would be on a warm day. In contrast, boiling only occurs at the boiling point of the liquid. Applications One way to produce table salt is to evaporate saline water in evaporation ponds, a technique used by people for thousands of years. Gusarov, A. V.; Smurov, I. (2002). "Gas-dynamic boundary conditions of evaporation and condensation: Numerical analysis of the Knudsen layer". Physics of Fluids. 14 (12): 4242. Bibcode: 2002PhFl...14.4242G. doi: 10.1063/1.1516211. Temperature: The greater the temperature of the liquid and its surroundings, the faster the rate of evaporation. On a global scale, the amount of water evaporating is about the same as the amount of water delivered to the Earth as precipitation.During evaporation only the molecules near the liquid surface are changing from liquid to vapor. During boiling the molecules inside the volume of the liquid are also changing to vapor. For this reason during evaporation no bubbles are formed, instead they are formed during boiling. Steam table with sensible, latent and total heat, and specific volume at different gauge pressures and temperatures. The evaporation heat (enthalpy) of water at temperature at 20 o C is 2454 kJ/kg . The heat supply required to maintain the temperature of the water in the swimming pool can be calculated as To reduce the energy consumption and to avoid moisture damages in building constructions it is common to use heat recycling devices with heat pumps moving latent heat from the air to the water in the swimming pool. Water Surface Evaporation Calculator Evaporation is when a liquid becomes a gas without forming bubbles inside the liquid volume. If bubbles are formed we are talking instead about " boiling".

Evaporation can be defined as the process through which a liquid (generally water) is converted into a gas/vapour without being heated to its boiling point. The key factors that affect the rate of evaporation of a liquid are: Fuel droplets vaporize as they receive heat by mixing with the hot gases in the combustion chamber. Heat (energy) can also be received by radiation from any hot refractory wall of the combustion chamber. Pre-combustion vaporizationLiquids are known to not have any definite shape – they assume the shape of their container. Therefore, the greater the surface area of the container (or the greater the surface occupied by the liquid), the greater the number of liquid molecules present at the surface. The larger the number of liquid molecules are at the surface, the larger the number of molecules that will break away from the liquid and become a gas at a given point of time, which contributes to an increase in the rate of evaporation. Humidity of the Surrounding The use of evaporation to dry or concentrate samples is a common preparatory step for many laboratory analyses such as spectroscopy and chromatography. Systems used for this purpose include rotary evaporators and centrifugal evaporators. identify the part played by evaporation and condensation in the water cycle and associate the rate of evaporation with temperature. Evaporation is a very important part of the water cycle. Heat from the sun, or solar energy, powers the evaporation process. It soaks up moisture from soil in a garden, as well as the biggest oceans and lakes. The water level will decrease as it is exposed to the heat of the sun. increase the moisture content in the air - may increase the condensation and damage of the building constructions for indoor pools