Answer:
F. The mesosphere contains fewer oxygen molecules than the stratosphere.
Step-by-step explanation:
The layers of the atmosphere are divided into:
1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermosphere
5. Exosphere
The troposphere extends from the earth surface to about 10km upwards. This is the region of the greatest atmospheric pressure and where all weather conditions arises. In the troposphere, the higher one goes the cooler it becomes.
The stratosphere lies on the troposphere and it is about 50km from the top of the troposphere. The stratosphere is the region where ozone, an oxygen molecule, forms a layer. The higher you go in the stratosphere, the warmer it becomes.
The mesosphere is about 90km thick and it has less gas density. It extends from the top of the stratosphere upwards. The gases here are sparse and atmospheric pressure is lesser than that of the surface. Here, the higher you go in the mesosphere, the cooler it becomes.
Only option F is correct: the mesosphere contains fewer oxygen molecules than the stratosphere.