I'll give you the answer and also I'll provide you with the illustration. It heps to get the idea of sharps, steps, half-steps etc. Very useful thing. You can use it as these topic is tricky enough. So here are the answers:
1.The solfege syllable for the dominant note G is D. sol.
2. C. C to B-flat
3. A. G to A-flat
4. The interval between any note and its nearest neighbor with the same letter name called A. and octave.
5. A sharp symbol next to a note makes that note A. one half step higher
I hope everything is clear with note circle.
