The presence of H-C bonds in these compounds makes them more susceptible to attack by species in the troposphere. Hence, they are less likely to find their way to the stratosphere and release chlorine atoms. CFCs and CCl4 are not so readily attcked. See text page 64 for discussion of CCl4 and methyl chloroform.
Excited states are of higher energy.
The types of excited states referred to in this chapter are translational, where a third body carries off excess energy as heat, and electronic. The term 'steady state' of ozone concentration means that the concentration is approximately constant. The rates of formation and destruction of ozone are equal, so that the concentration of ozone does not change. This is not necessarily an equilibrium concentration. 2-18 The sinks for Br, HBr and bromine nitrate, are a lot less stable than those for Cl.