Answer
The redundancy lies in the fact that if you know the chemical symbol of the element, then you don't need $Z$, which is the atomic number. If you locate the chemical symbol on the periodic table, you will also find the atomic number, which is located in the same box as the chemical symbol for the element.
Work Step by Step
The redundancy lies in the fact that if you know the chemical symbol of the element, then you don't need $Z$, which is the atomic number. If you locate the chemical symbol on the periodic table, you will also find the atomic number, which is located in the same box as the chemical symbol for the element.
