Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons in their nuclei. Because the number of protons (which defines the element) remains the same, isotopes share the same atomic number but have different mass numbers.
For example:
- Carbon-12 has 6 protons and 6 neutrons.
- Carbon-14 has 6 protons and 8 neutrons.
Despite being chemically similar, isotopes can have different physical properties and nuclear behaviors. Some isotopes are stable, while others are radioactive and decay over time, releasing radiation. These radioisotopes are widely used in medicine (e.g., cancer treatment, imaging), archaeology (radiocarbon dating), and nuclear energy.
Isotopes are essential for understanding atomic structure, nuclear reactions, and various applications across science and technology.