Perhaps you have noticed the dull, white substance that appears on an aluminum screen door. This substance is aluminum oxide, Al2O3, and it forms from the reaction of aluminum metal, Al, and oxygen, O2. Which of these chemical equations is correct for this reaction? A. Al + O2 → Al2O3
B. 2 Al + O2 → Al2O3
C. 2 Al + 3 O → Al2O3
D. 4 Al + 3 O2 → 2 Al2O3

Which of the following is not a good technique for managing used oil? a) have specific, labeled catch pans available for technicians who are collecting oil b) spills in your shop and any releases on pavement or outside should be poured down a drain c) do not use oil containers for antifreeze or other non-similar fluids d) be prepared for oil spills with the proper absorbents

21. consider the following chemical reaction: n2+ o2 2 no if 10.0 g of n2 reacts with excess oxygen then how many grams of no can be formed? a) 10.7 g b) 21.4 g c) 32.9 g d) 42.8 g page 4 of 8

The fact that the total amount of energy in a system remains constant is a(n)