Pb^2+ is the LEAD cation
208 is isotopic mass number
protons = 82
neutrons = 208 – 82 = 126
electrons = 80 ( Since it has ‘lost’ two electrons to be comes ‘Pb^2+’. )
Pb⁺² is properly named the lead(II) ion. It is also called the plumbous ion. It is one of the two lead ions. The other is lead(IV), Pb⁺⁴, called the plumbic ion.
lead +2 ion
mass number 208
All lead atoms and ions have 82 protons.
Number of neutrons
= mass number – number of protons
= 208 – 82
Atoms are neutral, meaning they have the same number of protons and electrons. A lead atom has 82 protons and 82 electrons, but here we are talking about a lead 2+ ion. It has a positive charge of +2, meaning it has 2 fewer electrons than a lead atom, hence it has 80 electrons.
In the notation 208Pb, the 208 is the mass number.