A1.1.3 COHESION OF H2O MOLECULES (w/o xylem)

Question 1

Define cohesion

Answer 1

The force of attraction between the molecules of the same substance/kind (similar molecules).
→ H2O ⇄ H2O

Question 2

Molecular structure of surface tension (S.T.)

Answer 2

• H2O molecules bond with the surrounding similar molecules
  → Bc there isn’t any above them in the surface, cohesive forces r stronger w/ the ones around/below them

Question 3

Properties of S.T.

Answer 3

• S.T. must be broken for objects to move thru the surface
• A habitat for animals
  → Water striders & basilisk lizards
• S.T. weakens with:
  → ↑ pollution (i.e. detergent)
  → turbulent/rough water
• ↑ surface area = ↑ ability to sustain S.T.
• Breaking S.T. requires a lot of energy
  → the force exerted by water striders is not enough to break the cohesive forces of the H2O molecules