Water is Pretty Cool

     Water makes up 70% of the world--97% of which is salt water, 3% freshwater--with 2% still underground and 1% in rivers and lakes across the world. The water cycle recycles the water over the years, and the stages include:
1. Evaporation: Water is turned from a liquid form into water vapor in the atmosphere.
2. Condensation: Water vapor collects and turns into droplets of water in the atmosphere
3. Precipitation: Water droplets that are heavy enough fall to the earth as rain, hail, snow, or sleet.

     Water, as a molecule (H2O) is polar, with oxygen as the negatively charged part and the two hydrogens as the positively charged parts. Because they attract each other (opposites attract) it forms a bond between hydrogen and water, called a hydrogen bond. Hydrogen bonds are not as strong as some other bonds, but they are strong enough to hold onto the water molecule, and once broken, can reform again with other water molecules.

     Ice and water are curiously related. Ice has a lesser density than water, because the hydrogen bonds don't efficiently line up the water molecules, which results in the water molecules being more spread out and less dense than water. Water is also used mainly as a solvent because it is polar--therefore, it's called a polar solvent. Polar solvents are usually better at dissolving other polar solutes. However, water and oil do not mix because oil is not polar--therefore, they don't mix well at all.