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Understanding Water

Water Chemistry

Water Chemistry Water is a compound substance composed of the chemical elements hydrogen and oxygen. The water molecule consists of two atoms of hydrogen and one atom of oxygen - H2O It existing in gaseous, liquid, and solid states. At room temperature water is a odorless, tasteless and transparent liquid. The physical and chemical properties of water are complicated and not fully understood. Since the oxygen atom is much heavier, by weight the water molecule is 1 part hydrogen and 8 parts oxygen.

Part of the molecule is negatively charged and part positively charged. This charge structure is a result the molecule being bent in a special way. Water molecules tend to attract each other, making water kind of "sticky." since opposite electrical charges attract, completely pure water is a poor conductor of electricity Water is relatively incompressible.

Figure: Water Molecule

H = Hydrogen Atom     O = Oxygen Atom

Water Molecule

Water is colorless in small amounts, but has a bluish tinge in large quantities. The tinge results from the small amount of particulates in the water. Different colors can penetrate deeper into the water. Red is the color that can be seen the furthest down into the water because red light has the shortest wavelength and the most energy.


Water is sensitive to ambient temperatures. When cooled to its freezing temperature (0°C, 32°F, under standard pressure), water changes to a colorless, crystalline solid (ice) Water at 4°C as a liquid is more dense than ice. Unlike other liquids, water expands when it freezes. At ordinary ambient temperatures, water converts to a vapor or gaseous state (evaporates). When water is heated to its boiling point (100°C, 212°F, under standard pressure), it vaporizes to steam.


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