1. The problem statement, all variables and given/known data I was doing an experiment containing gas or vacuum tubes "type 884 tube". It contains argon gas but when reading about triodes and cathode ray tubes, they are generally referred to as vacuum tubes - the type 884 tube is a triode, so does that mean it is a gas filled triode? or is it a vacuum tube containing a gas? This is mostly just a terminology question - if this isn't allowed, I apologize but I just thought that asking you would be the best way to get an informative answer. Also, I realize this seems quite silly but it has been irritating me.