Question

Which part of the atom has to stay the same for it to be the same element? number of neutrons number of protons number of electrons number of protons, neutrons, and electrons

Answer 1

The answer is the number of protons.

If you change the number of protons the element changes whereas changing the number of electrons makes an ion and changing the number of neutrons makes an isotope. :)

Answer 2

Answer is: number of protons.

The atomic number (Z) determines total number of protons and uniquely identifies a chemical element,

There are 118 unique elements discovered so far.

The first chemical element is hydrogen (atomic number is 1) and the last is oganesson (atomic number is 118).

Elements are scheduled in periodic table, ordered by their atomic number.