Thank you for bringing to my attention the recent International Union of Pure & Applied Chemistry report “Atomic weights of the elements 2009” (C&EN, Dec. 20 ...

Students use the terms isotope, atomic number, mass number, and atomic mass. Atomic Theory: Structure of the Atom: Students use the terms isotope, atomic number, mass number, and atomic mass to ...

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Note: This video is designed to help the teacher better understand the lesson and is NOT intended to be shown to students. It includes observations and conclusions that students are meant to make on ...