Exosphere
True
The small planet of Mercury has almost no atmosphere. If there was ever an atmosphere on that planet, the sun likely burned it off.
Mars has almost no atmosphere. APEX=MERCURY has no atmosphere.
Troposphere contains nearly all of the atmosphere's clouds. This is for 2 reasons: first, almost all water vapor is contained in this layer. Second, the air is inherently unstable, since it is warmest at the bottom. The causes the air to always want to rise, creating clouds under the right conditions.
The thermosphere is the "hottest" layer of the Earth's atmosphere. As the outermost layer with substantial numbers of molecules, it receives the most direct radiation from the Sun. However, despite the high molecular temperatures measured in this layer (as high as 2500°C or 4530°F), the matter is tenuous compared to the lower atmosphere. An object within the thermosphere would absorb very little total heat energy. Almost all satellites, and the International Space Station, orbit within the thermosphere. The layer periodically varies in thickness, stretching from about 80 kilometers in altitude to between 250 and 500 kilometers. The thermosphere.
Exosphere
troposphere
troposphere
true
The Exosphere is the layer in the atmosphere that is closest to outer space.
The stratosphere contains almost no water vapor.
troposphere
True
Correct, more than 90% of it
indeed it does. each successive layer contains less and less gas. (the last layer is almost like outer space actually) so yes the troposhere contains almost all atmospheric gas
The composition of the atmosphere of Saturn is almost entirely made up of hydrogen, at 97%, and helium, at 3%. It also contains trace amounts of methane, at about 0.05%.
There are a few layers to the atmosphere however the Troposphere is the largest part of the atmosphere containing 75% of its mass. However the Troposphere contains 99% of the water vapour on the planet as well as Earth's aerosols. It is also where all weather phenomenon will occur.