Is the atomic number of an element the number of protons in the nucleus of an atom? If not, what is it?

1 Answer
Aug 9, 2017

Yes, the atomic number of an element is the number of protons each atom of that element contains in the nucleus.

For example, referring to a periodic table:

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The atomic numbers of each element are listed above the element's symbol.

Can you tell me how many protons are in an atom of #"Zr"# (zirconium) or #"Re"# (rhenium) or #"O"# (oxygen)?