Yes.
Any scale can start on any note. That's why there are 12 major scales.
The supertonic of any scale is the second degree of the scale. Therefore, the supertonic of C major is D.
The subdominant in any major scale is the fourth note. So, in C major, the subdominant is the F.
7 note scale. Any mode of major scale with no chromatic alterations
The fifth note of C major scale is G. The fifth note of any scale is always called the dominant.
Yes, G-flat major.
There aren't any.
look for any accidenatls in the scale. If there are no accidentals, then it's a major scale, vise versa. All the sharps and flats should be included in the key signature of the scale.
Because none of the notes in that scale are on any of the black keys.
Any major or minor scale with eight notes starting on Do (the tonic note).
Eight, the same as in any major or minor scale.
Let's do C major. C D E F G A B. So there are 7. If you count the octave (C), then 8. This is the same with any major scale.