Chemistry › Isotope
Mendeleev · Isotope
Iron-56
Iron-56: atomic number 26, mass number 56, with 26 protons and 30 neutrons.
IsotopeFe
5626Fe
Protons26
Neutrons30
Electrons (neutral)26
The proton count fixes the element: 26 protons identify Iron. Mass number 56 is the total number of protons and neutrons.
A neutral Iron-56 atom also has 26 electrons. Changing neutrons changes the isotope; changing electrons changes the charge.