Question A2: The ground state oxygen atom

Write down a kinetic equation (net rate law) for the concentration change of ground-state oxygen atoms

with time, where t represents time, neglecting equation (A.2).

Integrate your rate law, to afford an analytical expression showing the actual variation of the ground-state

oxygen atom concentration with time, under conditions of constant irradiation, and that all species M are

present in excess. Make sure you identify appropriate boundary conditions.

Use the steady-state approximation and your kinetic equation to determine the steady-state concentration

of ground-state oxygen atoms.

Then, identify whether the steady-state hypothesis is a suitable approximation to apply to ground-state

oxygen atoms in atmospheric modelling.

Comment on any similarities or differences you have found in the application of the steady-state

approximation for the reactive intermediates (O and O) considered in Questions A1 and A2.