Radical Reactions

Question 1

NO radicals from lightening

Answer 1

Propagation
NO. + O3 => NO2. + O2
NO2. + O => NO. + O2

Overall reaction
O3 + O => 2O2

Question 2

CFC radicals

-conditions

Answer 2

Initiation
CF2Cl2 => CF2Cl. + Cl.

Propagation 
Cl. + O3 => ClO. + O2
ClO. + O => Cl. + O2
Termination
Just collect all the radicals

Overall
O3 + O => 2O2

-conditions
UV from the stratosphere
Single CFC molecule can promote the breakdown of 100000 ozone molecules