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How to find the mass number of an element?

Best Answers

To calculate the mass number of a specific element, find the number of protons and the number of neutrons that element has. Then, add them together. A periodic table of elements is needed to complete this task. read more

Subtracting an element's mass number from its atomic mass tells you the number of protons in its nucleus. Finding the Mass Number The best place to look for an element's atomic mass number is in the periodic table. read more

The mass number should also not be confused with the standard atomic weight (also called atomic weight) of an element, which is the ratio of the average atomic mass of the different isotopes of that element (weighted by abundance) to the unified atomic mass unit. read more