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
By mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O 2. This is an important part of the atmosphere and diatomic oxygen gas constitutes 20.8% of the Earth's atmosphere.