Of protons neutrons and electrons, which of these can never change in atom during an ordinary chemical or physical change

The number of electron or proton of an atom can change depending on the chemical bond and the other chemical it is bonded with; an atom can either gain or lose electron. However, the number of neutrons of an atom can never change, this is the primary identity or signature of an atom.

neutrons

a. they are both space stations

happy to

pls mark as brainliest.