Question

the table below shows the atomic mass of three isotopes of uranium (u).
isotope atomic mass
u - 234 234
u - 235 235
u - 238 238
what characteristic is different in each isotope?
the position in the periodic table of the elements
the net charge of the nucleus
the mass of the protons in the nucleus
the number of neutrons in the nucleus

Explanation:

Isotopes of an element have the same number of protons (and thus the same atomic number, same position in the periodic - table, and same net nuclear charge). The mass number of an isotope is the sum of protons and neutrons. Since the number of protons is the same for isotopes of the same element, the difference in their atomic masses is due to the different number of neutrons.

Answer:

The number of neutrons in the nucleus