Is the treble clef heighest picth on staff?

The treble clef is not the highest pitch on the staff. The treble clef is used to indicate the pitch of notes in the higher range, but the highest possible pitch on a standard musical staff is the "G" located above the staff. This note is written on a leger line, which is a short horizontal line added above the staff to accommodate notes beyond the normal range of the staff. The treble clef does not determine the highest pitch that can be played, it simply indicates that the notes written on the staff are in a higher range compared to the bass clef.