Lecture 3: Water & Life

Why is hydrogen bonds important for water molecules?

they contain 2 polar covalent bonds so they have partial charges. These partial charges can form hydrogen bonds and it gives several emergent properties. These include cohesion/adhesion, temperature moderation, density of ice, and it is a good solvent

What is cohesion?

the binding together of like molecules often by hydrogen bonding

What is adhesion?

The attraction between different kinds of molecules

What is transpiration?

the evaporative loss of water from a plant. Cohesion + adhesion + evaporation = transpiration

What is surface tension?

How difficult it is to stretch/break the surface of a liquid

What is temperature moderation?

water moderates air temperature by absorbing heat from air that is warmer than the water, and releasing stored heat to air that is cooler than the water

What is specific heat?

the amount of heat that must be absorbed or lost for 1 gram of a substance to change its temperature by 1 C

What is a hydration shell?

when ions are in water and they get surrounded by water molecules in a formation

What is the properties of ice?

ice is around 10 percent less dense than liquid water, crystalline structure of ice leaves more spaces, and it loses energy and molecules stop moving so hydrogen bonds do not break

What can water dissolve?

it dissolve polar molecules