Question : When an iron nail is dipped into a coloured copper sulphate solution, its colour changes to_____.

Option 1: green, blue

Option 2: blue, green

Option 3: blue, yellow

Option 4: yellow, blue

Question : The gas causing acid rain in an industrial area is

Option 1: carbon dioxide

Option 2: carbon monoxide

Option 3: sulphur dioxide

Option 4: methane

Question : The gas used to extinguish fire is

Option 1: Neon

Option 2: Nitrogen

Option 3: Carbon dioxide

Option 4: Carbon monoxide

Question : An electric iron has a heating element made of :

Option 1: Copper

Option 2: Tungsten

Option 3: Nichrome

Option 4: Zinc

Question : The gas that causes suffocation and death when coal or coke is burnt in a closed room is

Option 1: Methane

Option 2: Ethane

Option 3: Carbon Monoxide

Option 4: Carbon Dioxide