Vacuum kettle
Try out cool boiling!
Safety
- Carefully review the general safety advice on the back of the box cover before starting the experiment.
- Observe safety precautions when working with boiling water.
- Disassemble the setup after the experiment.
Disposal
- Dispose of solid waste together with household garbage.
Scientific description
Liquid water 
in an open vessel 
gradually turns into gas 
and flies away in a process known as evaporation. Hot liquid 
evaporates more quickly than cold liquid 
, which is why you can even observe the steam rising from hot drinks with the unaided eye.
Typically, steam rises from water because evaporating into the air 
is easier than into the liquid or the vessel in which it is located. But if you heat 
water to a certain point, it begins to evaporate so intensely that it starts to evaporate inside itself—to boil. The bubbles 
in boiling water are made of steam .
How intense the evaporation must be for the water to boil depends on air pressure 
. By lowering the pressure , you make it easier for water to boil, and it begins to do so at a lower temperature than it does at atmospheric pressure.
