Answer the following:
1. _______ is a usually a by-product of nitrogen and oxygen and used to fill incandescent light bulbs.
2. _______ refers to the average interplay of all the interacting elements over a short period of time.
3. _______ is an ultramafic rock found in the mantle which is composed of minerals like olivine and pyroxene.
4. The sharp boundary between the earth?s crust and the mantle is known as ________.
5. What is diastrophism?
6. Iron, gold, copper and silver belongs to what type of minerals?
7. ______ refers to the way a mineral reflects light.
8. ______ is the Greek term for mountain generating.
9. ______ is a colorless, odorless gas that occurs abundantly in nature as the chief constituent of natural gas and as a product of the anaerobic bacterial decomposition of vegetable matter under water.
10. The coldest zone of the atmosphere is ________.
11. _______ are low, shapeless rain clouds. They are dark gray in color.
12. What are the segments on the Earth?s outer surface called?
13. The vertical movement of air due to uneven heating of the earth?s surface by the sun is called_______.
14. ________ refers to the water vapor in the air.
15. This layer of the atmosphere is very thin, but it is where aurora takes place and also responsible for absorbing the most energetic photons from the sun.
16. Lying below the crust at a depth ranging from 5-90km is the ________ which is composed mostly of oxides and sulfides of Mg, Fe, and Si. It is solid but has the ability to flow like a liquid.
17. ________ means the biological environment.
18. -22. Give at least three interacting elements of weather.
23. ______ describes how a mineral appears to reflect light, and how brilliant or dull the mineral is.
24. ______ is a rain or melted snow that freezes into ice pellets before hitting the ground.
25. _______ is part of the world climatic regions which is characterized by lack of warm summer and has an average mean temperature of less than 10 degrees Celsius.
26. _______ is an aggregate of ice crystals that form into flakes.
27. Halite and limestone are examples of _______ sedimentary rock.
28. Directly above the stratopause, extending from 50-80 km above the earth?s surface is the ______ which is a cold layer and thick enough to slow down meteors hurtling into the atmosphere.
29-30 Give at least two instruments used to measure the ozone molecules.
II. Differentiate the following terms:

1. Felsic and mafic rocks
2. Plutonic and volcanic igneous rocks
3. Clastic, organic and chemical sedimentary rocks
4. Weather and climate
5. Inner core and outer core