The main constituents of atmosphere are _______.

• 
• 
• 
• 

In desert areas, the water vapor content is ____.

• different

• higher

• low

• constant

Combustion cannot take place without ________.

• water

• carbon

• air

• zinc

On blowing a gas X, the colourless solution in the test tube turns milky. Identify the gas X.

• Nitrogen

• Oxygen

• Carbon dioxide

• Water vapour

The household fuel in urban India is _____.

• LPG

• CNG

• coal

• kerosene oil

The products of combustion of fuels are __________.

• nitrogen & carbon dioxide

• water vapour & carbon dioxide

• water vapour & nitrogen

• carbon dioxide & oxygen

Carbon dioxide is produced by living beings during the process of _______.

• rusting

• combustion

• photosynthesis

• respiration

The amount of carbon dioxide present in the atmosphere is ____.

• 1%

• 0.03%

• 2%

• 3%

A white-coloured powder (P) on hydration turns to blue. Identify P.

• Copper sulphate

• Magnesium sulphate

• Sodium sulphate

• Aluminium sulphate

A cut potato turns black when kept open to the atmosphere but packaged potato chips do not. Which gas is present in the chips packet?

• Oxygen

• Nitrogen

• Carbon Dioxide

• Helium