What does a water molecule look like?

An oxygen molecule that is bonded to two hydrogen molecules through covalent bonds. its bent in a tentrahedren

How do water molecules bond to each other?

The oxygen of one molecule forms a hydrogen bond with the hydrogen molecule of the other

Water molecules are ___

Polar

what does hydrophilic mean?

Is attracted to water molecules

What does hydrophobic mean

Is repulsed by water molecules

What does cohesion mean?

Water molecules forming hydrogen bonds with other water molecules

What does adhesion mean?

Water molecules forming bonds with other polar surfaces

Cohesion vs adhesion

Cohesion = water sticks to water

Adhesion = water sticks to other polar surfaces

What is surface tension? what causes it?

a phenomenon that results in the tendency of a liquid’s surface to resist rupture when placed under tension or stress. This is due to cohesion - where weak hydrogen bonds hold the liquid together.

Why are cohesive and adhesive forces important for life?

They play a role in many water-based processes in biology, including the movement of water to the tops of trees and the drainage of tears from tear ducts in the corners of your eyes

What are the two most stressed examples of cohesion and adhesion forces in AP biology

A strider bug using surface tension to skate on top of the water and water moving up the stem of a plant.

Why is ice less dense then water

when the temperature drops and water freezes, water molecules form a crystal structure maintained by hydrogen bonding (as there is too little heat energy left to break the hydrogen bonds). Water molecules are pushed farther apart than they are in liquid water.

Because ice is less dense then water it ___

Floats

Why is the density of ice important to life?

In lakes and ponds, a layer of ice forms on top of the liquid water, creating an insulating barrier that protects the animals and plant life in the pond below from freezing.

What is specific heat capacity?

The amount of heat needed to raise the temperature of one gram of a substance by one degree Celsius.

Does water have a high or low specific heat capacity?

A high specific heat capacity.

Why does it take a lot of heat to increase the temperature of liquid water?

Some of the heat must be used to break hydrogen bonds between the molecules.

What is heat of vaporization?

the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature.

Does water have a high or low heat of vaporization?

High

What is evaporative cooling?

As water molecules evaporate, the surface they evaporate from gets cooler.

Why is evaporative cooling important to life?

In humans and other organisms, the evaporation of sweat, which is about 99% water, cools the body to maintain a steady temperature.

Why is water being an excellent solvent important to life?

Water has the unique ability to dissolve many polar and ionic substances. This is important to all living things because, as water travels through the water cycle, it takes many valuable nutrients along with it.