राजभाषा भारती का

The gas used for filling weather balloons is-

The fuel that is used in modern submarines is -

Formation of ozone hole is maximum over

Petroleum is a mixture of-

 Alum stops bleeding in minor cuts because of

The most reactive among the halogens is-

The element used in the manufacture of safety matches is —

Milk tastes sour when kept in the open for sometimes due to the formation of-

The important ore of aluminium is-

______is the process in which acids and bases react to form salts and water