GUIDE深度 · Deep dive
Ions and Isotopes
Ions are charged after atoms gain or lose electrons: losing electrons gives a positive charge, gaining gives negative. Isotopes have the same protons but different neutrons; neutrons = mass number - atomic number.
Ions
Na+ lost one electron.
Cl- gained one electron.
Charge goes at the upper right.
Isotopes
Same protons, different neutrons.
Mass number = protons + neutrons.
FAQ
Can an ion also be an isotope?
Yes; isotopes can also gain or lose electrons.
Can neutrons be negative?
No; mass number must exceed atomic number.