Silver (symbol: Ag) is a metal and has only 1 ion (`Ag^+`), which is formed when the silver atom loses 1 electron. Metals generally have a tendency to lose one or more electrons, and this results in the formation of metal cations. Silver also forms a cation (`Ag^+`). Since there is only 1 positive charge on it, this shows that only 1 electron has been lost from the silver atom.
Note that when a metal atom loses an electron to form a cation, its mass number does not change, since the number of protons and neutrons remains the same and only an electron has been lost. Similarly, the atomic number of the resulting cation is the same as that of the atom, since no protons have been lost.
Thus, the silver cation will have the same atomic number and same mass number as that of the silver atom.
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