GATE Questions

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Iron reacts with oxygen in the presence of moisture or water to form a red oxide called rust and the reaction involved is called as Redox reaction.

Government is to set to introduce new Rs. 100 coin with image of former Prime Minister Atal Bihari Vajpayee.

The air around us is a mixture of gases, mainly nitrogen and oxygen, but containing much smaller amounts of water and other gases.

Earth's atmosphere is composed of many gases. Their percentages by volume is given by::

 
78% Nitrogen,

21% Oxygen,

0.9% Argon, and

0.03% Carbon dioxide 

And very small percentages of other elements.

Groundwater is all the water that has penetrated the earth's surface and is found in one of two soil layers. The one nearest the surface is the "zone of aeration", where gaps between soil are filled with both air and water. Below this layer is the "zone of saturation", where the gaps are filled with water.

Humidity means the amount of watervapour present in the atmosphere. It depends on weather, location and temperature of the place.