<span>A key signature is most helpful in determining the "root and the scale used" a piece of music. Other purpose of key signature is that it tells you what key to play in order to avoid accidentals. Accidentals are symbols that modifies the pitch of the note, either making it into a sharp, a flat.</span>
Answer:
5
Explanation:
An ion with 5 protons, 6 neutrons and a charge of +3 has an atomic number of 5
