Question

Explain:
(i) Sponge though compressible is a solid
(ii) Gases completely fill the vessel in which they are kept.

Answer 1

Hello there!
(i.) Sponge is a porous solid. It has minute holes in which air is trapped when we press it, the air is expelled out and we are able to compress it.

(ii.) It is the property of gases, that it can expand.

Answer 2

I) Sponge regains it's shape after it has been left uncompressed.This,it is a solid,as a solid maintains it's physical conditions....
II) Gases have very losely tight atoms.Whenever,they are kept in a container having a lot of space, they fill the complete vessel with their atoms.It is the property of their atoms to do so.