water

• each water molecule has 2 delta positive hydrogens and 1 delta negative oxygen with covalent bonds holding them together and between water molecules there are hydrogen bonds
• high boiling point

  • because intermolecular hydrogen bonds require lots of energy to break
  • it forms a high percentage of cytoplasm and since it’s liquid, chemical reactions of cellular metabolism can occur within
• water is less dense as solid than solid

  • because the crystal lattice structure formed requires water molecules to move further apart so there’s less water molecules in a given space
  • ice insulates water underneath by providing a cover from cold air enabling aquatic life to survive
  • ice forms a habitat for terrestrial organisms e.g polar bears
  • nutrients can be circulated in aquatic environments due to different densities of water at different temperatures
• high specific capacity + thermal stability

  • requires lots of energy to raise temperature due to its hydrogen bonds
  • stable temperature maintained for enzyme-controlled reactions
  • thermoregulation for organisms
  • aquatic organisms have an environment with a stable temperature
  • cells are less prone to damage from changes in environmental temperature
• high latent heat of vaporisation

  • water requires lots of energy for it to evaporate making it able to act as a coolant
  • dogs panting and lizards gaping cools them
  • sweating
  • water is liquid over a large range of temps
  • transpiration stream keeps leaves cool
• solvent

  • due to water’s polarity it allows to dissolve lots of substances - the ionic lattice from the solutes dissociates and bonds with the water ions
  • ions from charged and polar molecules dissolve in water allowing chemical reactions to occur
  • water is a reactant or some reactions e.g hydrolysis
  • acts as a transport medium e.g blood, phloem, xylem
• adhesion

  • the force of attraction between water molecule and different molecules
  • the formation of bonds aids capillary action - the process of water moving up a narrow tube against gravity
  • water’s attraction to xylem walls allows the transpiration stream
• cohesion

  • attraction between water molecules due to the hydrogen bonds
  • contributes to capillary action and SURFACE TENSION - ability of surface of a liquid to resist external force
  • surface water can act as habitat for some insects e.g pond skater
  • column of water forms in xylem so it can be moved through transpiration stream
• water is colourless

  • it can transmit visible light
  • plants underwater can photosynthesise
• high tensile strength

  • a column of water won’t pull apart under tension
  • water can be lifted large distances by forces applied e.g transpiration in tall trees