What determines the temperature of a layer of the atmosphere apex?

The temperature of the layers of the atmosphere are determined by the composition of gasses, the amount of gasses, and its alleviation.

The composition of gasses in a certain layer is crucial for the temperature because some gasses are very good preservers of heat, while others are not preserving heat well.

The amount of gasses is very important, because the more gasses there are that can preserve heat, the higher the temperature will be, and vice versa.

The alleviation is important because at different heights, there's different amount of gasses, different types of gasses, different amount of sunlight ...

the way the layer interacts with solar radiation