The right option is; b. an individual oxygen atom combines with an oxygen molecule
Ozone is formed when an individual oxygen atom combines with an oxygen molecule.
Ozone (O3) is an allotrope of oxygen that has three atoms in the molecules instead of the normal two. Ozone is poisonous and it is a highly reactive blue gas that is generated from oxygen by electrical discharge. Ozone is formed in the atmosphere when some molecules of oxygen (O2) absorb energy from the ultraviolet (UV) radiation and break apart to form single oxygen atoms. These atoms then merge together with the remaining oxygen (O2) to form ozone (O3) molecules. In the upper atmosphere, ozone functions as a shield, protecting the earth from ultraviolet radiation.
Ans.
Ozone gas (O3) is a toxic, colorless gas, with pungent smell and acts as a powerful oxidizing agent. It is formed from the oxygen by UV light (ultralight light) and electrical sparks.
Formation of ozone takes place in two steps. During first step, an oxygen molecule (O2) is photolyzed and produces two atoms of oxygen (2 O). In second step, one of these oxygen atom (O) combines with another oxygen molecule and form ozone gas (O3).
Thus, the correct answer is option b). 'an individual oxygen atom combines with an oxygen molecule.'
