Ice is less dense than water and thus it floats. Water is called the universal solvent because the polarity of water is responsible for its capacity to act as a solvent in a solution. Covalently bonded molecules like sugars have regions of partial positive and negative charges. This causes them to have an attraction for water molecules and dissolve in it. Fats lack these polar regions and for this reason are insoluble in water.
Water molecules tend to ionize or dissociate into hydrogen ions and hydroxide ions.
An acid is any substance that gives off hydrogen ions when dissolved in water. A base is any substance that accepts hydrogen ions when dissolved in water. They are called alkaline. The ph scale measure the concentration of hydrogen ions. A ph above 7 is basic and below is acid.