Question

Why the ballon can not be filled without an air?​

Answer 1

A balloon is a balloon that flies in the air because it is filled with a gas less dense than air or lighter than air. It is tied to a thread to prevent it from flying up in the air. Blimps have displaced zeppelins (which are not balloons) as the dominant form of airship.

Answer 2

because air exerts pressure equally in all direction so, balloon is filled with air because, does not affect the latex of balloon but, if it would be filled with liquid or solid then it create pressure towards downward of the latex and the balloon would burst.