https://www.khanacademy.org/science/ap-chemistry-beta/x2eef969c74e0d802:atomic-structure-and-properties/x2eef969c74e0d802:mass-spectrometry-of-elements/v/isotopes 2022-09-07T08:21:01.673602243Z Isotopes Isotopes are atoms of the same element with different numbers of neutrons. Because they contain different numbers of neutrons, isotopes have different atomic masses. The average atomic mass of an element is calculated by taking the weighted average mass of the element's naturally occurring isotopes. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/0a383f46-3f5b-4b2c-ad63-6338ab2a71be_1280_720_base.png Isotopes Isotopes are atoms of the same element with different numbers of neutrons. Because they contain different numbers of neutrons, isotopes have different atomic masses. The average atomic mass of an element is calculated by taking the weighted average mass of the element's naturally occurring isotopes. https://cdn.kastatic.org/ka-youtube-converted/ShC3VoxxW3g.mp4/ShC3VoxxW3g.mp4 328 Isotopes https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atoms-isotopes-and-ions/x2613d8165d88df5e:isotopes-and-ions/v/hs_isotopes 2025-12-03T14:30:51.007256483Z Isotopes Isotopes are atoms of the same element with different numbers of neutrons. Since isotopes of an element have different numbers of neutrons, they also have different masses. The sum of the number of neutrons and protons in an atom is called its mass number. Isotopes can be represented in writing using isotope notation. Wieteke Holthuijzen video https://cdn.kastatic.org/ka_thumbnails_cache/df82de5e-1e56-4266-8fc4-45e02720aca1_1280_720_base.png Isotopes Isotopes are atoms of the same element with different numbers of neutrons. Since isotopes of an element have different numbers of neutrons, they also have different masses. The sum of the number of neutrons and protons in an atom is called its mass number. Isotopes can be represented in writing using isotope notation. https://cdn.kastatic.org/ka-youtube-converted/HDniYwGEl0o.mp4/HDniYwGEl0o.mp4 250 Isotopes https://www.khanacademy.org/science/biology/history-of-life-on-earth/radiometric-dating/a/atomic-number-atomic-mass-and-isotopes-article 2021-04-29T07:51:16Z Atomic number, atomic mass, and isotopes Fundamental properties of atoms including atomic number and atomic mass. The atomic number is the number of protons in an atom, and isotopes have the same atomic number but differ in the number of neutrons. article https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atoms-isotopes-and-ions/x2613d8165d88df5e:isotopes-and-ions/e/understand-isotopes 2026-04-07T23:36:17.218592739Z Understand: isotopes Check your understanding of isotopes in this set of free practice questions. Lauren Rosebrugh exercise https://www.khanacademy.org/science/strengthened-shs-chemistry-1/x174677b2bfa4bea2:1st-quarter/x174677b2bfa4bea2:untitled-75/e/atomic-number-mass-number-and-isotope-composition 2025-02-05T10:28:14.374739025Z Atomic number, mass number and isotope composition In this exercise, we will solve questions on finding out atomic number, mass number and isotope composition. Revathi exercise