What does the Periodic Table not help scientists do? A. Identify the most common compounds found on Earth.
B. Learn more about elements based on the groups and periods they are in.
C. Make predictions about what kind of properties new elements might have.
D. Determine how many protons, neutrons, and electrons an element has.

Nitric acid can be formed in two steps from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming natural gas. in the first step, nitrogen and hydrogen react to form ammonia: (g) (g) (g) in the second step, ammonia and oxygen react to form nitric acid and water: (g) (g) (g) (g) calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .