Question

Which have different numbers of electrons?

different ions of an element
different isotopes of an element
the nucleus of an element
each of the atoms of an element

Answer 1

The atomic number has the symbol Z. Different elements have different atomic numbers; therefore, atoms of different elements contain different numbers of protons (and electrons). Oxygen has the atomic number 8; its atoms contain 8 protons and 8 electrons.

Answer 2

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