In your reading, perhaps you saw that in 1995, three chemists were awarded the Nobel Prize for their studies involving the ozone layer. First, in 1970, scientist Paul Cruzen hypothesized that nitrogen oxides could participate in the destruction of ozone. He was concerned that high-flying jet aircrafts, such as the Concorde, could be the culprit that created the nitrogen oxide. He proposed the following mechanism to show how these compounds were involved in the destruction of ozone: Step 1: NO(g) + O3(g) → NO2(g) + O2(g)
Step 2: NO2(g) + O(g) → NO(g) + O2(g)

The rate equation for this reaction was found to be:

Rate of reaction = k[NO][O3]

Looking at this rate law, which of the above steps would be the rate determining step and why?