The number of protons in isotopes of an element is the same.The mass number of an isotope tells you the number of protons plus the number of neutrons. Mass number = number of protons + number of neutrons â¢ Carbon has three isotopes: carbon-12, carbon-13, and carbon-14.
The 2nd time gap was long and came during Gaiden when Sarada and Boruto were 11 and by the time The Last : Boruto The Movie was aired, Boruto and Sarada were already 12 thus making Sasuke 33 years old at the final movie.
In the manga, Sasuke goes back to the Leaf(for his important 'work') in chapter 618.He decides to join Konoha in the war in chapter 627.And in chapter 631, he declares his wish of becoming the Hokage. Since he's still fighting alongside Naruto in the war, he hasn't completely 'returned' to the Leaf yet~.