How thick is the atmosphere?

The atmosphere is the last layer of the planet, after which outer space begins. At the moment, it is customary for scientists to call that part of the gas envelope, which rotates with the Earth on its axis, and where aircraft can use air rudders for maneuvers, namely the atmosphere. And this layer is about 100-120 kilometers thick. But the gas shell is much thicker and reaches the mark of 500-1000 kilometers.