How was the ozone layer formed on Earth?

How was the ozone layer formed on Earth?
  1. Through a process of condensation
  2. Through a process of evaporation
  3. Through a process of combustion
  4. UV rays from the sun

Solution

UV rays from the sun broke up water into hydrogen and oxygen and the lighter H₂ escaped and Oxygen combined with ammonia and methane to form water, CO₂ and others. The ozone layer was formed.

Asked in: NCERT

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