During a chemical reaction, the amount of energy a) may increase or decrease depending on the type of reaction b) increases as it is converted from one form to another c) decreases as it is converted from one form to another d) is constant as it is converted from one form to another

Iknow the answer is a but i don't know why

This is a characteristic of the elements in the periodic table that shows a pattern. it may increase or decrease across or down the table.

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 .