4.1 Meaning :
1. Nitrogen – the chemical element of atomic number .
2. Troposphere –the lowest region of the atmosphere .
3. Stratosphere –the layer of the earth’s atmosphere above the troposphere .
4. Mesosphere– atmosphere above the stratosphere and below the thermosphere .
5. Exosphere –the outermost region of a planet’s atmosphere .
6. Meteorites –a piece of rock .
7. Precipitation –rain, snow, sleet that falls to condenses on the ground .
8. Convictional – believed .
9. Orographic – relating to mountains .
10. Evaporation – the process of changing from a liquid or solid into vapor .