Learn about atomic number, mass number, and isotopes in this Khan Academy video.

Learn about atomic number, atomic mass, and isotopes in this Khan Academy article.

"The atomic mass of chlorine-3 5 is ... 75 atoms have a mass number of 35, and 25 atoms have a mass number of 37. About the mass number for the isotope chlorine 37: Its nucleus contains …

Learn about different types of radioactive decay in nuclear physics on Khan Academy.

Earlier on in the "Atoms, compounds and ions" playlist the weighted average of atomic masses was described as the relative atomic mass, but later on it was described as average atomic …

If you're seeing this message, it means we're having trouble loading external resources on our website. If you're behind a web filter, please make sure that the domains *.kastatic.org and …

Learn to identify elements from mass spectrum data with this worked example on Khan Academy.

可汗学院 - Khan Academy

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