Questions

A search engine is a set of programs which enables users to search documents and files ihe world wide web.

Common search engines are Google, Yahoo, Bing,...

All India Radio founded in 1930.

With over 420 radio stations in about 23 languages & 179 dialects.

AIR is one of the largest radio broadcasters in world.

It also has 99.19% population coverage & 18 FM channels.

The most important determinant of consumer spending is the level of income.

When water is cooled from 4°C to 0°C, its density decreases.

When water cools from 4°C to 0°C, ice crystals begin to form because the water is approaching its freezing point. When water freezes, the water molecules form a lattice that increases the volume. As a result, the density decreases. This is why ice will float on top of water; ice has a lower density than the water.

A chemical reaction in which involves the absorption of heat from the environment is called a Endothermic reaction. 

Examples : Dissolving ammonium chloride in water, photosynthesis, melting ice cubes, mixing of potassium chloride with water,...

In the contrast, chemical reactions involving release of heat are known as exothermic reactions.

Examples : Combustion, coal is burnt, mix of CaO with water,...