Question

Ozone layer is mainly made up of :-
1. Ozone gas
2. Carbon dioxide gas
3. Nitrogen gas
4. Hydrogen gas

Answer 1

Correct Answer - Option 1 : Ozone gas

The correct answer is Ozone gas.

• ​Ozone is a colorless gas made up of three oxygen atoms.
• Ozone is not emitted directly into the air but is formed through chemical reactions between natural and man-made emissions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. 
• These gaseous compounds mix like a thin soup in the ambient, or outdoor, air, and when they interact with sunlight, ozone is formed.
• Ozone can be split into two major types: Stratospheric Ozone and Ground-Level Ozone.
• Stratospheric ozone
  • It is also known as the "ozone layer" that forms high in the atmosphere, 6-30 miles above the earth's surface, when intense sunlight causes oxygen molecules (O2) to break up and re-form as ozone molecules (O3).
  • These ozone molecules form the ozone layer and are commonly referred to as "good ozone."
  • At concentrations as high as 12,000 ppb (the EPA considers anything over 70 ppb to be unhealthy for human health and welfare) this ozone protects and shields people, trees, crops, property, and microorganisms from the harmful effects of the sun's ultraviolet light. 
• Ground-level ozone
  • It forms just above the earth’s surface (up to about 2 miles above ground) and impacts human, animal, and plant respiration.
  • Although ground-level ozone is less concentrated than stratospheric ozone, its impacts on human health and welfare make ground-level ozone "bad ozone."
  • Ground-level ozone is an irritant and can negatively affect human health and welfare.
  • Weather plays a substantial role in the formation of ground-level ozone.
  • Ground-level ozone concentrations typically are highest on days warm/hot days with low humidity when the wind is light or stagnant.