Water is the most important molecule on this planet
Why should we care about understanding water?
Here are 7 reasons for that.
With the water molecule we have:
Variations in weather patterns
From climate effects, to the water cycle, to different patterns of water precipitation.
Living beings
Living beings (water helps bring ions and gasses together in a chemical soup. It is from this mixture that early cells developed).
A universal solvent
Water is able to facilitate chemical reactions, energy storage, as well as dissolve gasses like oxygen and nitrogen.
No temperature extremes
Avoidance of temperature extremes: the sand gets hot enough to burn one's feet, but water will not.
A very efficient transport vehicle
Water can transport of matter from one place to another as well as from one environment ton another (rivers, oceans, ice, steam engines, etc).
No acid/base extremes
Avoidance of chemical extremes (water is able to buffer acids, bases, and high levels of ions).
Multiple phases in a narrow temperature range
Water is one of the few molecules that can exist in multiple phases in a narrow temperature range (at 1 atmospheric pressure). It is this temperature range (0º - 100ºC/32º - 212ºF) that allows the top 6 reasons to take place.