Gene therapy is designed to introduce genetic material into cells to compensate for abnormal genes or to make a beneficial protein. If a mutated gene causes a necessary protein to be faulty or missing, gene therapy may be able to introduce a normal copy of the gene to restore the function of the protein.
Noble gases have complete valence electron shells
Since the atomic number of calcium is 20. The number of protons is also 20.
That seems to be standard notation
