What is the significance of the number of neutrons in an isotope?

The number of neutrons in an isotope is significant because it differentiates isotopes of the same element. Isotopes are variants of a particular chemical element that share the same number of protons (and hence are the same element) but have different numbers of neutrons. This variation in neutron count leads to differences in mass and stability among isotopes. For example, carbon-12 and carbon-14 are both isotopes of carbon, having 6 protons each, but differ by the number of neutrons: carbon-12 has 6 neutrons, while carbon-14 has 8 neutrons. This neutron difference can lead to varying physical properties, such as differing stability and radioactive decay rates, which are important in both biological and geological contexts. Thus, identifying the neutron count is crucial for distinguishing between the isotopes of the same element.