* Left: Totally
fill a Liquemin bottle with water. Turn it upwards down.
* Photo 2: Repeat
the same experiment with water, which was mixed with a drop of liquid soap.
* Photo 3: Suck 1
ml of water into a syringe with a thin blunted needle.
* Totally remove air bubbles
and adjust exactly to 1 milliliter (ml).
* Photo 4: Distribute
0.1
ml water on a plastic surface as micro drops.
* Right: Repeat
the former experiment, replacing the water by soap water.
Observations
and explanations: Soap
causes a reduction of
surface tension in water:
1. Water easily flows out
of the small bottle. 2. Water distributes into smaller drops
(28 instead of 17 / 0.1 ml).
3. Each dropf touches a
greater area of the plastic surface.