Assuming that the space within the solid or liquid is vacuum, it is not matter because there is no mass inside. However, there is a volume. The volume inside a solid would have regular straight sides because atoms of a solid is compactly arranged. For liquids, the space could be irregular curves and paths because the atoms in a liquid are free-flowing.
Oxygen has 6 valence electrons, so B
Here the chemical bond formed between iron and chlorine is an ionic bond, we can check this either through two ways, looking and identifying that Fe is a metal and Cl is a nonmetal, and thus would only allow for ionic bonds to be formed, I or by taking the difference in electronegativity and seeing if it is greater than or equal to 1.3. To be ionic.
Two properties of gasses are that the have no defined shape or volume.
good luck my man