Isotopes - GCSE Chemistry Definition

Isotopes are different forms of the same element that have the same number of protons but different number of neutrons in their nuclei. This means isotopes have the same atomic number but different mass numbers. For example, carbon has isotopes like carbon-12 and carbon-14; both have 6 protons, but carbon-12 has 6 neutrons while carbon-14 has 8 neutrons. Although isotopes of an element have similar chemical properties because they have the same number of electrons, they can have different physical properties. Some isotopes are stable, whereas others are radioactive and can decay over time, releasing radiation. Understanding isotopes is important in fields like medicine, archaeology, and nuclear energy.