20 A place where no air present will be called as what? Give example.
A place where no air is present is called Vaccum. Example: space
A perfect vacuum can be defined as a space with no particles of any state (solid, liquid, gas).
55 Air present in the atmosphere will be defined as what? Name the major constituents of air. Give their volume proportions in air.
give some example where bromine is present
give reason:-
alvera will be considered as an example of solid