Question

which contributing factors cause the thermosphere to be warmer than the mesosphere?
gases are more dense in the thermosphere and absorb energy easily.
sunlight is reflected by the abundant gases, oxygen and nitrogen, in the mesosphere.
the abundance of hydrogen gas causes explosions, sending heat into the stratosphere.
ultraviolet radiation is absorbed, and fewer air molecules cause the thermosphere to heat quickly.

Explanation:

• The thermosphere has gases that are more dense compared to the mesosphere. Denser gases can absorb energy more easily. When energy (such as from solar radiation) is absorbed, it contributes to heating the layer.
• Ultraviolet radiation being absorbed in the thermosphere is a key factor. The absorption of this high - energy radiation by the relatively dense gases in the thermosphere leads to heating.
• Let's analyze each option:
• Option 1: Ultraviolet radiation is absorbed, and fewer air molecules (this is incorrect as the thermosphere has more gas density compared to the mesosphere in the context of energy absorption for heating).
• Option 2: Hydrogen gas causing explosions and sending heat to the stratosphere (not relevant to the thermosphere - mesosphere temperature comparison).
• Option 3: Sunlight reflected by abundant gases in the mesosphere (opposite of what causes heating; reflection would not contribute to heating the thermosphere more than the mesosphere).
• Option 4: Gases are more dense in the thermosphere and absorb energy easily (correct as denser gases can absorb more energy, leading to higher temperatures in the thermosphere compared to the mesosphere).

Answer:

Gases are more dense in the thermosphere and absorb energy easily.