Gunpowder consists of a mixture of : 

An organism which can monitor air pollution is –  

The colour of the ocean appears to be blue because the sunlight falling on it is-

Why does a Blackboard appear black in colour? 

The atoms of Germanium, Arsenic, Selenium and Bromine contain _____ shells.

The organ which stores carbohydrates as glycogen in the human body is 

The maximum limit in decibels of sound intensity above which a person cannot hear—

The purpose of Choke in tube light is