Questions

Glass is made from heating of sand. To melt sand to make glass, the temperature needed is above 1800 deg celcius.

An ionic bond is formed between two molecules when transfer of valency electrons take place between them. 

Agronomy is a branch of agriculture that deals with the study of crops and the soils in which they are produced.

Afghan-India Friendship Dam is previously called as Salma Dam between India and Afghanistan on Hari river.

Materials that usually allow electricity to pass through them are called Good conductors of electricity.

Conductors conduct electrical current very easily because of their free electrons.

Examples are :: Aluminium, Gold, Copper, Silver

Materials that do not allow or oppose electrical current & make poor conductors are called Insulators.

Examples are :: Glass, Plastic, Wood, Air,...

A duty is a task that is to be obeyed, followed and respected by all the citizens of the country or state.

When heated any substance, the molecules move apart from each other. Alike in the air the molecules move apart from each other. We know that the warm air is lighter than the cool air. Since after heating air gets warmer, it floats up and the cool air comes down to occupy the warm air place.