If there is magic anywhere on Planet Earth, it's in the water.
Di-polar: Water is a di-polar molecule. This results from the arrangement of the hydrogen atoms (which meet at a 105 deg. angle across the oxygen) and gives water a slight electrical charge.
Surface tension: Water's polarity results in a slight electrical charge, which causes water molecules to be attracted to other water molecules.
Basically, water carries with it a glue which it uses to gum up the works.
Water and Gravity: Water is stuff and is therefore subject to the laws of physics - including gravity.
Water contains an immense amount of gravitational potential energy, which is converted to kinetic energy when the water is allowed to move.
This kinetic energy is used to perform all sorts of work: from the transport of sediments to turning electric generators in hydroelectric plants.
Specific Heat: Water has a relatively high specific heat. This means that it changes temperature very slowly.
Because of this, any large body of water (like the ocean) tends to act as a "thermal storage unit" which can be used to store and transfer heat energy, and moderate climates.
Phase changes: All substances can exist in either the solid, liquid, or gaseous (vapor) phase.
Changing from one phase to another requires the addition or removal of heat energy.
Ice + heat goes to Water + heat goes to Steam
Water is the only known substance which can exist in all three states at normal surface temperatures and pressures.
Water and density: As a substance loses heat energy, molecular motion slows and the atoms come closer together. This results in a higher specific gravity (mass/unit volume). All known substances abide by this rule, except for water.
The density of water does increase as it cools (as it should), but at 4 C the density vs. temperature graph goes the other way and the density actually begins to decrease.
This decrease continues until the solid state is achieved (at 0 C), at which temperature the density vs. temperature graph resumes its normal trace.
This "magic" property of water is no small thing. Think of what would happen if ice was more dense than water.
Water and pH: Describe acid/base pH scales
Water has a pH of 7, and is therefore neither (or both) an acid or base.
Actually HOH, and both a proton acceptor and donor, so it's both.
Because of this, water is considered a "universal solvent" which will, if given enough time, chemically attack any and all substances.
We'll cover this in greater detail later during our discussion of chemical weathering.