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
The most abundant gases in the atmosphere are nitrogen at 78 percent and oxygen at 21 percent, while the trace gases methane, neon and helium make up around one-tenth of 1 percent of the atmosphere. Oxygen, nitrogen and argon are classified as permanent gases because their percentages always remain the same.