Isotopes are atoms of the same element that have the same number of protons (same atomic number) but different numbers of neutrons.
Because they have the same atomic number, isotopes belong to the same element and show the same chemical properties. However, their atomic masses differ, which can affect their physical properties (like density, stability, and radioactivity).
Example:
- Carbon-12 (¹²C) → 6 protons, 6 neutrons
- Carbon-14 (¹⁴C) → 6 protons, 8 neutrons
Both are isotopes of carbon, but carbon-14 is radioactive, while carbon-12 is stable.
Key Points about Isotopes:
- Same element, different mass numbers.
- Same chemical behavior, different physical properties.
- Some isotopes are stable, others are radioactive (used in medicine, archaeology, and nuclear energy).