meaning - Which word should i use? Open and Opened

May I know whether open or opened I should use in this sentence?
These cases are opened?
or
These cases are open?

I want to use in, Once these cases _____, then it will be moved to "Opened Tab".
Or I should use, Once these cases have been opened ?

Answer

Both sentences are grammatical. They mean different things. "These cases are open" is an adjective construction that describes these cases. "These cases are opened" is a passive construction that declares an event of opening these cases to take place. For instance, if a judge could open cases by deeming them to be open, he could say "These cases are opened" (and bring his gavel down) to accomplish the opening of the cases.