Key Concepts: Isotopes & Radioisotopes

Core Definitions

• Isotope: Atoms of the same element with different numbers of neutrons (same protons, different mass numbers).
• Radioisotope: An unstable isotope that undergoes radioactive decay.
• Atomic Mass: The weighted average mass of all naturally occurring isotopes of an element.
• Mass Number: The total number of protons and neutrons in a specific isotope.
• Isotope Notation: Written as Element-mass number (e.g., Carbon-14) or with superscript mass number.
• Percent Abundance: The percentage of each isotope found naturally; used to calculate atomic mass.