Helium is added to the oxygen supply of deep sea divers because it is............

• less poisonous than nitrogen

• lighter than nitrogen

• readily miscible with oxygen

• readily miscible with oxygen

SMOG is a combination of 

• Air and water vapour

• Water and smoke

• Fire and water

• Fire and water

Why is Carbon Monoxide a pollutant?

• Reacts with haemoglobin

• Makes nervous system inactive

• It reacts with Oxygen

• It reacts with Oxygen

From the following, who was the first women speaker of Lok Sabha?

• Sushma Swaraj

• Margret Alva

• Meera Kumar

• Meera Kumar

Why does ice covered in sawdust not melt quickly?

• Sawdust does not allow the air to touch the ice

• The water is absorbed by sawdust

• Sawdust is a bad conductor of heat

• Sawdust is a bad conductor of heat

26.

Which one of the following weeds is effective in controlling water pollution caused by industrial effluents?

• Parthenium

• Elephant grass

• Water hycinth

• Water hycinth

The most pure form of carbon among the options is

• Anthracite

• Lampblack

• Graphite

• Graphite

______________ gives hardness to stainless steel.

• Zinc

• Lead

• Carbon

• Carbon

Activated Charcoal is used to remove colouring matter from pure substances by _____________

• Bleaching

• Oxidation

• Adsorption

• Adsorption

Chernobyl disaster is the result of pollution by

• Oil spill

• Acid rain

• Carbon dioxide

• Carbon dioxide