physical properties of water

• Specific heat capacity

  A measure of the energy required to raise the temperature of 1 kg of a substance by 1C
• Specific heat capacity


  A measure of the energy required to raise the temperature of 1 kg of a substance by 1C
• Water has a higher specific heat capacity (4200 J/kg/C) compared to air (1000 J/kg/°C)
• Specific heat capacity of water

  • Relatively large amount of energy is required to raise its temperature
  • Due to the many hydrogen bonds present in water
  • It takes a lot of thermal energy to break these bonds and a lot of energy to build them, thus the temperature of water does not fluctuate greatly
• Advantage of high specific heat capacity for living organisms


  • Provides suitable, stable aquatic habitats since water temperatures will change more slowly than air temperatures
  • Able to maintain a constant temperature as water is able to absorb a lot of heat without wide temperature fluctuations
  • Vital in maintaining temperatures that are optimal for enzyme activity
• Artic and sub-artic species

  • Ringed seal (Pusa hispida)
• The density of ice is lower than the density of liquid water, which means that ice floats on water
• This forms a habitat for the seals both on the floating ice sheets, as well as below the ice
• Thermal conductivity


  The ability of a substance to conduct heat
• The thermal conductivity of water is almost 30 times higher than that of air, which makes air a very good insulator for organisms living in colder climates
• Black-throated loon (Gavia arctica)


  • A species of diving bird which spends much time underwater catching its prey
  • Their feathers trap an insulating layer of air, which assists them with regulating their body temperature
• The seal relies on a layer of fat called blubber to insulate it from the outside air
• Ice in its environment will also form an insulating layer above the water, since the thermal conductivity of ice is much lower than liquid water
• This increases the sea temperature below the ice as thermal energy is trapped
• Buoyancy


  The ability of an object to float in water
• The black-throated loon has solid bones, unlike the hollow bones that most bird species have to assist them with flight
• This increases the weight of the bird and compresses air out of the lungs and feathers during a dive - air sacs
• The layer of blubber under the ringed seal's skin will improve the buoyancy of the animal, along with providing a layer of insulation against the cold temperatures of its habitat
• Viscosity


  The resistance of a fluid to flow
• The viscosity of water is much higher than air, which enables the black-throated loon to fly through the air without much friction
• The body shapes of both the loon and seal makes it easy for them to move through water
• Adaptations for movement through water


  • Seal has flippers to propel itself
  • Loon uses its webbed feet to push against the water and the lateral location of its feet reduces drag as it moves through water
• Specific heat capacity


  A measure of the energy required to raise the temperature of 1 kg of a substance by 1C
• Water has a higher specific heat capacity (4200 J/kg/C) compared to air (1000 J/kg/°C)
• Reason for high specific heat capacity of water

  Many hydrogen bonds present in water
• It takes a lot of thermal energy to break these bonds and a lot of energy to build them, thus the temperature of water does not fluctuate greatly
• Advantage of high specific heat capacity for living organisms


  • Provides suitable, stable aquatic habitats since water temperatures will change more slowly than air temperatures
  • Able to maintain a constant temperature as water is able to absorb a lot of heat without wide temperature fluctuations
  • Vital in maintaining temperatures that are optimal for enzyme activity
• Artic and sub-artic species

  • Ringed seal (Pusa hispida)
• The density of ice is lower than the density of liquid water, which means that ice floats on water
• This forms a habitat for the seals both on the floating ice sheets, as well as below the ice
• Thermal conductivity


  The ability of a substance to conduct heat
• The thermal conductivity of water is almost 30 times higher than that of air, which makes air a very good insulator for organisms living in colder climates
• Black-throated loon (Gavia arctica)


  • Their feathers trap an insulating layer of air, which assists them with regulating their body temperature
• Ringed seal


  • Relies on a layer of fat called blubber to insulate it from the outside air
• Ice in its environment will also form an insulating layer above the water, since the thermal conductivity of ice is much lower than liquid water
• This increases the sea temperature below the ice as thermal energy is trapped
• Buoyancy


  The ability of an object to float in water
• To overcome the problem of buoyancy, the black-throated loon has solid bones, unlike the hollow bones that most bird species have to assist them with flight
• This increases the weight of the bird and compresses air out of the lungs and feathers during a dive - air sacs
• For the ringed seal, the layer of blubber under its skin will improve the buoyancy of the animal, along with providing a layer of insulation against the cold temperatures of its habitat