What makes a chord a specific chord is the notes that are played at the same time. Doesn't matter where the notes are on the neck, just so long as the notes are specific.

As for the scale value. Well, chords are derived from scales. If we didn't have scales then we'd have no way to form chords (no convenient way anyway). A scale is a selection of notes within an octave. A chord is a selection of notes within a scale that are played at the same time. An arpeggio is the same thing as a chord only instead of playing the notes at the same time, you playing them as individual notes.