Why does the thermosphere have the highest temperature of all the atmosphere layers?

Answer 1

It is affected most directly by the suns radiation

Answer 2

IT is closest to the sun

Answer 3

The thermosphere is the first layer of the atmosphere where there are enough heavier molecules (oxygen) to absorb a significant anount of the Sun's radiation. Below the thermosphere, much of the heat is dissipated by convective currents.
Although technically "hot", the gas in the thermosphere is so thin that it can pass little heat to other molecules, and loss of heat by radiation would still cool objects in this part of the atmosphere.
the sun's radiation strikes it first

Answer 4

The thermosphere experiences high temperatures because it absorbs high-energy solar radiation, particularly ultraviolet and X-ray radiation, due to its proximity to the Sun. However, despite its high temperatures, the thermosphere would not feel hot to us due to its extremely low density.

Answer 5

The sun's radiation strikes it first.

Answer 6

the suns radiation strikes it first (apex)