Which one of the following is not the part of atmosphere?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Lithosphere
The lithosphere is the solid outer shell of the Earth: the crust and the uppermost part of the mantle, the rocks and soil we stand on. It is one of the Earth's spheres beside the atmosphere (air), the hydrosphere (water) and the biosphere (life), not a layer of the air.
Why the other options are incorrect
Option (1) Ionosphere — Incorrect. It is the part of the upper atmosphere with charged particles that reflect radio waves.
Option (2) Stratosphere — Incorrect. It is the layer above the troposphere that holds the ozone layer.
Option (4) Troposphere — Incorrect. It is the lowest layer of the atmosphere, where all weather takes place.