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Ions and Isotopes in Atomic Structure
Ions are charged after gaining/losing electrons: losing gives positive, gaining gives negative. Isotopes are labeled by mass number, e.g. Fe-56; neutrons = 56-26 = 30.
Ions
Na+: 11 protons, 10 electrons.
Cl-: 17 protons, 18 electrons.
Isotopes
Fe-56: 26 protons, 30 neutrons.
The mass number goes at the upper left.
Write the mass number, protons and neutrons as three separate numbers before answering, so charge and isotope notation do not get mixed.
FAQ
Can an ion also be an isotope?
Yes; isotopes can also gain or lose electrons.
Can electron count be negative?
No; it cannot go below zero.