What is the definition of an element (periodic table elements)?

Newtons second law deals most cosely with

Which describes fat? a: a carbohydrate that produces energy b: a nucleic acid that directs cell function c: a lipid that stores energy d: a protein that speeds up a chemical reaction

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 .