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Su01 Distilled water a pure substance 1:
Colour, transparency, temperatures during freezing/melting and heating/boiling

Like any substance water has measurable and non-measurable properties.
* Left: Water is colourless and transparent only in the liquid state. Ice is white and turbid.
* Transfer 20 ml distilled water into an infusion bottle, close it by a stopper with a thermometer and a tubing
* Place it  into a deep freezer (inside a plastic container).From time to time observe and note the temperature.
* Photo 2 Oberservation: The temperature is the same during the whole process of freezing.
  The thermometer reads - 4°C, it was re-adjusted 0°C, the melting point of distilled water.
* Heat the bottle on an electric hotplate. Observation: 0°C as long as ice is present.
* After that: Quick rise of temperature.
* Photo 3 and rightObservation: Temperature remains the same during boiling:
  The thermometer read 98°, it was re-adjusted 100°C, the boiling point of water.
Explanation: 0°C and 100°C are melting point and boiling point of water. More explanation?