As far as compounds go all
compounds of metals are solid.
Compounds formed by
the combination two non-metals however, can be solid, liquid or
gas.
–However,
most of those that you will have to work with and be able to recognize
are gaseous.
You will need to memorize
them as you learn about their state.
–Water of course is liquid.
–But,
carbon dioxide (CO2) and carbon monoxide (CO), both oxides of carbons
are gaseous.
–Both sulfur dioxide (SO2)
and sulfur trioxide (SO3) are gaseous as well.
–Hydrogen sulfide (H2S)
is also gaseous.
–All
halides of hydrogen (hydrogen chloride, HCl, hydrogen bromide, HBr, and
hydrogen iodide, HI) are gaseous as well.