If the number of neutrons in the atom of an element are different then?

If the number of neutrons in the atoms of an element differs, they are referred to as isotopes of that element. Isotopes have the same number of protons and electrons, which means they exhibit similar chemical properties, but they have different masses and may exhibit different physical properties, such as stability and radioactivity. For example, carbon-12 and carbon-14 are isotopes of carbon, with 6 and 8 neutrons, respectively.