Heat
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Some selected temperatures in degrees Celsius (°C)
6000 surface of the sun
2500 filaments in a lamp
1535 iron melts
1063 gold melts
950 to 1200 flame of gas burner
800 match flame
357 mercury boils
327 lead melts
270 electrical soldering iron
220 smoothing iron (linen setting)
100 water boils
78 alcohol boils
57,8 highest air temperature ever measured on Earth
36 to 37 body temperature of healthy human being
0 water freezes
-39 mercury solidifies
-89,2 lowest air temperature ever measured on Earth
-180 air liquefies
-273 lowest possible temperature (absolute zero)
Evaporation
The conversion of a substance from the liquid state into the gaseous state
is referred to as evaporation.
There are two methods of evaporation: boiling and vaporization.
If water is heated to 100 °C, bubbles rise to the surface because the water
particles start moving rigorously as a result of the heat supply. The water
“boils”. The rising bubbles contain an invisible gas: water vapour.
Vaporization is the name given to the process when a liquid evaporates
at a temperature below its boiling point. In this case, only particles on the
liquid surface enter the gaseous state.
Condensation
The reverse process to evaporation, i.e. the conversion of a substance from
the gaseous state into the liquid state, is known as condensation.
Small droplets of liquid form from the invisible gas over the boiling water
upon cooling and can be observed as a cloud or mist.
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