6 . Chemical formula for water is A . NaAlO 2
B . H 2 O C . Al 2 O 3 D . CaSiO 3
7 . The gas usually filled in the electric bulb is A . nitrogen
B . hydrogen C . carbon dioxide D . oxygen
8 . Washing soda is the common name for A . Sodium carbonate
B . Calcium bicarbonate C .
Sodium bicarbonate D . Calcium carbonate
9 . Quartz crystals normally used in quartz clocks etc . is chemically A . silicon dioxide
B . germanium oxide C . a mixture of germanium oxide and silicon dioxide D . sodium silicate
10 . Which of the gas is not known as green house gas ? A . Methane
B . Nitrous oxide C .
Carbon dioxide D . Hydrogen
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