Question

in isotope of an element number of. ............are different

Answer 1

mass are different and neutron also

Answer 2

HEY MATE HERE IS YOUR ANSWER
===============================
$Different isotopes of the same element have the same atomic number. They have the same number of <b>protons</b>. The atomic number is decided by the number of <b>protons.</b> Isotopes have different mass numbers, though, because they have different numbers of <b>neutrons.</b>$
===============================
HOPE IT HELPS YOU