An element that has the same chemical properties as other atoms of the element but a different number of neutrons is called an isotope.

Here's why:

* Chemical properties are determined by the number of protons: The number of protons defines an element. For example, all carbon atoms have 6 protons. This is why all carbon atoms have the same chemical properties, regardless of how many neutrons they have.

* Neutrons affect the atomic mass: Neutrons contribute to the atom's mass but not its charge.

* Isotopes have the same atomic number but different mass numbers: The atomic number is the number of protons, and the mass number is the sum of protons and neutrons.

Example:

* Carbon-12 has 6 protons and 6 neutrons (mass number 12).

* Carbon-14 has 6 protons and 8 neutrons (mass number 14).

Both are isotopes of carbon, meaning they have the same chemical properties but different mass numbers due to different neutron counts.