The science cycle

weather

150

weather ballons 

weather ballons are large ballons that are used to carry equipment high into the atmosphere 

250

weather batellites

denoting an adjective that describes the class that a head noun belongs to and characterized by not having a comparative or superlative

climate

150

hopothsis

an educated guess

atmosphere

150

stratosphere

the layer of the earth's atmosphere above the troposphere

clouds

150

stratus

cloud forming a continuous horizontal gray sheet, often with rain or snow.

challenge

150

classifying 

denoting an adjective that describes the class that a head noun belongs to and characterized by not having a comparative or superlative