Isotopes include two or more versions of an atom of a given element that have the same number of protons but a different number of neutrons. An isotope symbol communicates information about the element (specifically, the symbol), the atomic number of that element, and the mass number of the specific isotope of the atom.
Isotopes - Questions 10 Help
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Version 1:
An isotope of aluminum contains 15 neutrons. Construct the symbol for the isotope.