Pre-AP Biology

Water Properties (2.2)Part 1

Earth2/3rds covered by water

Organisms are mostly water

Polar covalent bonding of water molecule See how each end(pole) has an electrical

charge?

Hydrogen bonding between water moleculesSee the central molecule bonding to the 4

outside molecules?

Cohesion

Water needs to get to the leaves for Photosynthesis.

Cohesion of water helps.

Adhesion See the water molecules binding to the Na+ or Cl-?

Which atoms of water are are attracted to the Na+?How about to the Cl-?

Surface Tension

Earth and Temperature

States of Water on EarthSolid, Liquid, and Gas

All four Hydrogen bonds have to break at the same time to allow water to evaporate

in a gas. That requires a lot of Energy.

HeatTotal amount of kinetic energy in a substance

There is so much energy moving through the metal, it glows.

TemperatureIntensity of all the heat in a substance

Which is showing the most intensity? Least?

Ice versus WaterIt is about molecule movement.

Evaporative Cooling

Expansion of water as it freezesLook at the distance between water molecules.

Which one looks more dense as a whole?

Water Floating

Life below the water

Pre-AP Biology

Water Properties (2.2)Part 2

Water dissolving “pulling apart” the salt See the water forming “shells” around the Na+ and Cl-?

Which molecule is the solvent? The solute?

HydrophobicWater “fearing” substances

See how they do not interact/mix?

Salt is hydrophilic in water.

Dissociation of Water

pH scaleThe “H” in pH is for Hydrogen

Measuring the concentration of Hydrogen ions (H+) within a substance

Buffering by Bicarbonate in blood Find Bicarbonate in the red blood cells

Acid Rain SourceBurning fossil fuels such as oil or gas

The effect of acid rain on plantsSee the dead trees?

Acid Rain and Concrete