In which layer of atmosphere radio wave gets reflected?

Top most layer of atmosphere is

Which layer of atmosphere is important for telecommunications?

Which layer has more cellulose ?

What in the value of frequency at which electromagnetic wave must be propagated for a certain region of atmosphere to have a refractive index of 0.5? Electron density for the region is 400 electrons/ cm^(3) .

In which regions of atmosphere, temperature increases with altitude and in which regions it decreases?

Write down the uses of radio waves.

The lower most layer of atmosphere, in which man and other living organisms exist, is called

Besides the lower layer, CO_(2) is also found in the upper layer of the atmosphere although it is heavier than O_(2) or N_(2) -explain.