How do you calculate how many protons/ electrons/ neutrons an elements isotopes have?
You should know that the elementary identity of an atom is uniquely based on its number of protons. IF its neutral (no net charge) the number of electrons will be the same. You should know this, if you don’t, you don’t know what an element is (from the atomic perspective). All atoms of an element have the same number of protons. In their uncharged state they also all have the same number of electrons. While an atom can gain or lose neutrons or electrons and remain the same element, any change in atomic number (proton number) means the atom is now a diffferent element. We can take off many electrons or add a few to an atom and you would need further information to determine how many we added or subtracted – but ALL we need is to know what element it is and what its charge is and we know how many electrons it has (if charge isn’t zero then the atom is ionized, an ion), Neutrons are more difficult since there are usually many possibilities. THe general rule of thumb is that you would expe