When was cancer first diagnosed?
and who was the first person to survive cancer?

If 22.5 liters of oxygen reacted with excess of hydrogen, how many liters of water vapor could be produced?

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit

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 .