Question

What properties do all solids, liquids, and gases have?

Answer 1

The properties that spring to mind are:

Mass, Volume, Density, Temperature

Explanation:

Hopefully it is clear that all solids, liquids and gases possess the listed properties.

Most other possibilities seem to be absent sometimes, or at least not an obvious property. For example, opacity may not be an obvious property of gases, though they may have some small effect on the passage of light - especially if the volume of gas is large. Refractive index applies to gases, liquids and some solids, but if a solid seems totally opaque then refractive index might not be an obvious property. Similarly viscosity is not obviously applicable to most solids.