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  1. Isotope - Wikipedia

    From left to right, the isotopes are protium (1 H) with 0 neutrons, deuterium (2 H) with 1 neutron, and tritium (3 H) with 2 neutrons. Isotopes are distinct nuclear species (or nuclides) of the same chemical …

  2. Isotope | Examples & Definition | Britannica

    Dec 12, 2025 · What is an isotope? An isotope is one of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table and nearly identical chemical …

  3. What Is an Isotope? Definition and Examples

    Sep 13, 2019 · An isotope is one of two or more forms of an element that have the same number of protons but different numbers of neutrons in the nucleus. Because they have the same number of …

  4. Isotope Basics | NIDC: National Isotope Development Center

    Isotopes are atoms of the same element that have the same number of protons (i.e., atomic number, "Z") but a different number of neutrons, meaning that their mass number, "A", varies. Take hydrogen, …

  5. What are Isotopes? | IAEA

    Aug 19, 2022 · Like everything we see in the world, isotopes are a type of atom, the smallest unit of matter that retains all the chemical properties of an element. Isotopes are forms of a chemical …

  6. What is an Isotope? - ChemTalk

    An isotope is an atom that has the same number of protons and a different number of neutrons. The atom is still considered the same element (still contains the same number of protons) as before but …

  7. DOE Explains...Isotopes | Department of Energy

    Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons. The number of protons in a nucleus determines the element’s atomic number …

  8. ISOTOPE Definition & Meaning - Merriam-Webster

    The meaning of ISOTOPE is any of two or more species of atoms of a chemical element with the same atomic number and nearly identical chemical behavior but with differing atomic mass or mass …

  9. 4.18: Isotopes - Chemistry LibreTexts

    Isotopes are atoms that have the same number atomic number, but different mass numbers due to a change in the number of neutrons. The three isotopes of carbon can be referred to as carbon-12 (6 …

  10. Isotopes: Definition, Meaning, Examples, Uses - Scienly

    Sep 22, 2024 · Definition: Atoms of an element which have the same atomic number but different mass numbers are called isotopes of that element. These isotopes are variants of the same element in …

  11. What Are Isotopes? Atomic Structure and Isotope Notation Explained

    Learn what isotopes are, how they differ by neutrons, and how to write isotope notation in this clear, student-friendly chemistry lesson.

  12. Isotope | Nuclear Regulatory Commission - NRC

    Among their distinct physical properties, some isotopes (known as radioisotopes) are radioactive because their nuclei emit radiation as they strive toward a more stable nuclear configuration. For …

  13. Isotope, what to remember | Orano

    When we talk about an isotope, we distinguish a type of atom that has the same number of protons but a different number of neutrons. Inside the atomic nucleus, the number of protons defines the chemical …

  14. Isotope Definition - Intro to Chemistry Key Term | Fiveable

    Isotopes of the same element have the same number of protons but different numbers of neutrons, resulting in different atomic masses. Isotopes can be stable or unstable (radioactive), and the …

  15. Radioactive isotope | Description, Uses, & Examples | Britannica

    Radioactive isotope, any of the species of the same chemical element that have different masses and unstable nuclei that emit radiation.

  16. ISOTOPE Definition & Meaning | Dictionary.com

    ISOTOPE definition: any of two or more forms of a chemical element, having the same number of protons in the nucleus, or the same atomic number, but having different numbers of neutrons in the …

  17. Isotope - Energy Education

    Unstable isotopes are the ones which undergo radioactive decay and in the process, change into other elements. Some unstable isotopes have very short half lives (less than a nanosecond), while others …

  18. Isotope - Simple English Wikipedia, the free encyclopedia

    Different isotopes of an element have different numbers of neutrons. As a result, they also have different mass numbers, which is the number of protons plus the number of neutrons. [2] . An isotope is …

  19. What is an Isotope: Explanation, Review, and Examples - Albert

    Jun 27, 2023 · We’ll cover what an isotope is, how to write its symbols, and methods to find its abundance. This post will also review important foundational concepts such as atomic structure, …

  20. Isotope Definition and Examples in Chemistry - ThoughtCo

    Feb 4, 2020 · Isotopes are samples of an element with different numbers of neutrons in their atoms. The number of protons for different isotopes of an element does not change. Not all isotopes are …

  21. isotope summary | Britannica

    isotope , One of two or more species of atoms of a chemical element having nuclei with the same number of protons but different numbers of neutrons.

  22. Stable Isotopes - MilliporeSigma

    ISOTEC® Stable Isotopes are useful for tracer studies in proteomics and metabolomics, agents for MRI / MRS, and in a wide range of other biomedical applications.

  23. Isotopes of hydrogen - Wikipedia

    Hydrogen (1 H) has three naturally occurring isotopes: 1 H, 2 H, and 3 H. 1 H and 2 H are stable, while 3 H has a half-life of 12.32 years. [4][nb 1] Heavier isotopes also exist; all are synthetic and have a half …