Question

why isotopes have same atomic number but different mass number.



Please it is urgent ​

Answer 1

Answer:

Different isotopes of the same element have the same atomic number. They have the same number of protons. The atomic number is decided by the number of protons. Isotopes have different mass numbers, though, because they have different numbers of neutrons.

Answer 2

Answer:

The isotope is one of the characteristic property of an element, they have same number of protons and different number of neutron. THEREFORE, they have same atomic number but different atomic mass number.