Chapter 3 - Water And Life Flashcards
What is a polar molecule?
When the opposite ends have opposite charges
Four properties of water that facilitate an environment for life:
- Cohesive behavior
- Ability to moderate temperature
- expansion upon freezing
- versatility as a solvent
What is cohesion?
The holding of water molecules together, by hydrogen bonds.
*Cohesion helps the transportation of water against gravity in plants.
What is adhesion?
An attraction between different substances, for example, between water and plant cell walls.
What is surface tension?
A measure of how hard it is to break the surface of a liquid
Related to cohesion
What is kinetic energy?
Energy in motion.
What is heat?
The measure of the total amount of kinetic energy due to molecular motion.
What does temperature do?
Measures the intensity of heat due to the average kinetic energy of molecules.
What is the Celsius scale?
A measure of temperature using Celsius (‘C)
What is a calorie (cal)?
The amount of heat required to raise 1g of water by 1’C.
What is the SPECIFIC HEAT of a substance?
The substance is the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1 cal/g/’C.
What is evaporative cooling?
The process where as a liquid evaporates, it’s remaining surface cools.
Explain why ice floats.
Ice floats in liquid water because hydrogen bonds in ice are more “ordered” making ice less dense.
At what temperature does water reach it’s greatest density?
4’C
What is a solution?
A liquid that is a homogeneous mixture of substances.
