Phase Inspection. 1  Framing: proper technique, boring & notching, wood grade, defective or missing members. 2  Window and door installation and water proofing. 3  Exterior sheathing and vapor barrier is correctly installed. â 4 Plumbing and Electrical inside the walls with correct nail stop shield placement.
Hydrogen is the lightest of the elements and is the most abundant element in the universe. (Also reference http://www.ducksters.com/science/chemistry/hydrogen.php) earth's atmosphere
Source: Oxygen is the most abundant element in the Earthâs crust, accounting for almost half of it by mass. More than half of the atoms in the Earthâs crust are oxygen atoms. About 86 percent of the mass of Earthâs oceans is oxygen â mainly in the form of water. Oxygen is the third most common element in the Universe, behind hydrogen and helium. It is obtained commercially from liquefied air separation plants. It can be prepared in the laboratory by electrolysis of water. Isotopes: 13 whose half-lives are known, with mass numbers 12 to 24.