A1.1.4 ADHESION

Question 1

Define adhesion

Answer 1

The force of attraction between different types of molecules/substances (dissimilar molecules)
→ H2O ⇄ other polar molecules/materials
* Water adhering w/ other materials = “getting wet”

Question 2

Define capillary action

Answer 2

The ability of a liquid to move through narrow tubes that results from cohesion, adhesion and surface tension

Question 3

Describe capillary action

Answer 3

Occurs when the adhesive forces > cohesive forces
→ H2O molecules r attracted to the walls of the container, ∴ creates a meniscus
→ ↓ Space = ↑ Water capillarity

Question 4

Where does capillary action occur

Answer 4

• Sand/Soil
  → H2O moves through pores in the soil through cohesion + adhesion
  → As water is dried out → H2O replaced by capillary action