Uhhh, this isn’t right at all…
First off, a chord is a set of notes (combined to be played simultaneously or one after the other as in an arpeggio) which includes what is commonly known as a triad (root, third and fifth). Chords or “harmonies” can be inferred with two notes (as if in the key of C major and playing an “F” and an “A” note with the F in the root which leans the listener toward the sound of the IV chord as long as the preceding chord is not something like a ii chord (D, F, A). Not all note combinations can be called a “chord” per se. For example, if you play the following chords on the piano adjacent to each other “C, C#, D, D#” that is a tone cluster and not a chord as thought of in a basic song writing. Such a chord might be used in modern classical music theory (and is by many composers), but is not something you would normally use during a bluegrass tune.
Chords can be extended however with various notes of the scale to which the origin of the chord belongs. For example, a C6 chord (C major 6) includes the 1, 3, 5 of the C major scale with the added 6 degree of the scale (C, E, G, A). Such a chord with the C in the root will have a major tonality with the A adding a relaxed color to it. However, the same notes with the A in the root position spells an Am7 ( A minor 7) chord (A, C, E, G) and has a completely different sound. In addition, some chords can have so many added notes that the chord can begin to lean toward sounding like a tone cluster like a G13 (G, B, D, F, A, C, E) which is essentially an entire G mixolydian scale played simultaneously. Of course, most folks will leave out the 9th (A) and the 11th (C ) from that chord and guitarists often favor also leaving out the 5th (D).
As far as the number of possible chords, that is only limited by your imagination. For example, If I were going to write a dominate chord (V) in the key of C major, I might spell such a chord G, B, D. Of course that is the most basic sound of such a chord and a stronger dominate chord might be spelled, G, B, D, F. And if I wanted to add color, I might spell it:
G, B, D, F, A (G9) or G, B, D, F, E (G13) or G, B, D, F, A# (G7#9) or G, B, D, F, Ab (G7b9) or G, B, D#, F, Ab (G7#5b9) or any number of interesting colors added to the standard dominant 7th chord sound. And that is only in root position as all of these chords could be inverted with any of the chord tones in the root or on top depending on how you would like to voice it.
To sum up, I don’t think most musicians would consider all the notes of the scale played at once as a “chord”, but rather as a note or tone cluster. A chord, in the modern sense of the word, is a harmony (often 3 or more notes but can be inferred by 2 notes) that can be defined as having a root, or a definable tonal center. A tone cluster does not really fit this description.