Troposphere
No. It is part of the hydrosphere.
Earth isn't in the atmosphere - the atmosphere is part of Earth.
ozone
Krypton is found in trace amounts in the atmosphere
oxygen
ozone
nitrogen
Upper Part
Yes. Hydrogen is part - albeit a very small part - of the Earth's atmosphere. Typically it makes up about 0.000055% of the atmosphere
ozone
The part of the earth's atmosphere that is closest to its surface is known as the troposphere.
Free Atmosphere or Free Air is a part of the atmosphere that lies above the Earths frictional influence.