2.1 Water Flashcards
(20 cards)
Why is water essential to
life?
- temperature regulation
- many reactions require
water - habitat
- acts as a solvent to transport substances around
the body
What role did water have
in the creation of living
things?
- formation of compartments
- allowed molecules to interact with each other
Which element is more
electronegative in water?
Oxygen
Why is oxygen more electronegative than hydrogen?
It has more protons,
pulling in the electrons.
cohesion
water molecules are attracted to each other
adhesion
attraction of water molecules to surfaces
tension
a force that stretches
something
How does capillary action
work?
cohesion and adhesion - the water will stick to the cellulose because they are both polar pulling the water up + water molecules stick to each other.
hydrophobic
non-polar and cannot dissolve in water
hydrophilic
polar and can dissolve in
water
What are the physical
properties of water?
buoyancy, viscosity, thermal conductivity, specific heat capacity
what is the definition of
specific heat capacity?
Measure of the energy required to raise the temperature of 1 kg of a substance by 1 celsius degrees
Why does water have a
high specific heat capacity?
many hydrogen bonds
Why is high specific heat
capacity important?
- stable habitat
- vital for enzyme activity
How does evaporation of
water help us to cool
down?
When it is hot, we sweat and the hydrogen bonds in water absorbs heat (it takes a lot of energy to break the bonds) and when there is enough heat, the water evaporates
taking the heat along.
What is the hypothesis
for the origin of water on
earth?
collisions with water-rich
asteroids
What type of bond is between the oxygen and two hydrogen atoms?
covalent bonds
What type of bond is between water molecules?
hydrogen
definition of viscosity
resistance of a liquid to flow
definition of buoyancy
Ability to float on water
