32. At the surface,
pull on the molecules is laterally and downward;
there is negligible intermolecular attractions
above the molecules (from the medium above, such as air).
SO, the net force on surface molecules is downward.
33. The result of this downward force is that
surface particles are pulled down until
counter-balanced by the compression
resistance of the liquid:
34.
35.
36. Surface molecules are compressed
more tightly together,
forming a sort of skin on the surface,
with less distance between them
compared to the molecules below.
37. Surface molecules also form a
much smoother surface than
one would expect from randomly
moving molecules.
38.
39.
40. This explains the characteristic rounded
shape that liquids form when dropping
through the air: The molecules are all
being pulled toward the center.
41. This explains the characteristic rounded
shape that liquids form when dropping
through the air: The molecules are all
being pulled toward the center.
42. Water in particular
has a very high
surface tension.
What property does
water have that would
give it such a strong
surface tension?
43. This is the water strider insect. Have you seen one?
