What contribution to atomic theory resulted from Albert Einstein's work? O A. A new understanding of what caused some elements to be
radioactive
B. A new model of the atom that described electrons as being in a
cloud
C. The discovery that different numbers of neutrons produced
isotopes
D. A new understanding that the nucleus contained protons and
neutrons

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 .