The molar mass of boron atoms in a natural sample is 10.79 g/mol. The sample is known
to consist of 10B (molar mass 10.013 g/mol)
and TB (molar mass 11.093 g/mol). What is
the percentage abundance of 10B?
Answer in units of %.

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 .