What is surface tension?
When you put water drops on surfaces treated with
SpotGuard or Spell,
the drops pile up into a dome because of surface tension. Surface
tension is produced by the force of attraction between water molecules.
Within the liquid, each water molecule is attracted to its neighboring
molecules, making them “stick” together. The water molecules at the top,
however, “stick” only to the water molecules next to and below them.
That’s because there are none above them. This unbalanced attractive
force causes the water to act as if it had a thin “skin” on the surface.
As you add more drops, the force of gravity becomes stronger than the
force of attraction among the water molecules at the surface.