Water

Question 1

What is the structure of a water molecule?

Answer 1

Two hydrogen and one oxygen
Covalent bond form between hydrogen and oxygen
Oxygen is slightly negative
Hydrogen is slightly positive

Question 2

What are the properties of water?

Answer 2

• It is a polar molecule
• It is a good solvent
• High heat specific capacity
• Large latent heat of vapourisation
• Cohesion
• Ice is less dense than water
• Incompressible

Question 3

How do the properties of water help organism to survive?

Answer 3

• It helps many metabolic reaction occur (solvent)
• Minimising temperature fluctuation in living things therefore it acts as a buffer (high specific heat capacity
• Evaporation provide a cooling effect with little water loss (Large latent heat of vapourisation)
• Enables effective transport of water in tube-like transport cells as the strong cohesion supports columns of water. As a result of strong cohesion the surface tension at the water-air boundary is high (Cohesion)
• Ice floats on top of water and form an insulation layer, this increases the chance of
• survival of organisms in large bodies of water as it prevents them from freezing (ice is less dense than water)
• Provides good support (incompressible)