Question

Sponge is a solid but it is compressed why?

Answer 1

Sponge is a solid but it can be compressed becoz of its material . It has some small pores where air is stored thus when we press it is compressed

Answer 2

Sponge molecules are spaced a lot among themselves.  They contain long molecules with a lot of gaps.

Sponge molecules have attraction between them, but less.  

There are air gaps among groups of molecules of the sponge material.  

They have very little elastic properties..