code: private String identifyAtomicSymbol(int atomicNumber) {
          String symbol;
          switch (atomicNumber) {
              case 1:
                  symbol = "H";
                  break;
              case 2:
                  symbol = "He";
                  break;
              case 3:
                  symbol = "Li";
                  break;
              case 4:
                  symbol = "Be";
                  break;
              case 5:
                  symbol = "B";
                  break;
              case 6:
                  symbol = "C";
                  break;
              case 7:
                  symbol = "N";
                  break;
              case 8:
                  symbol = "O";
                  break;
              case 9:
                  symbol = "F";
                  break;
              case 10:
                  symbol = "Ne";
                  break;
              case 11:
                  symbol = "Na";
                  break;
              case 12:
                  symbol = "Mg";
                  break;
              case 13:
                  symbol = "Al";
                  break;
              case 14:
                  symbol = "Si";
                  break;
              case 15:
                  symbol = "P";
                  break;
              case 16:
                  symbol = "S";
                  break;
              case 17:
                  symbol = "Cl";
                  break;
              case 18:
                  symbol = "Ar";
                  break;
              default:
                  symbol = null;
                  break;
          }
          return symbol;
      }
docs: TODO Update method comments with appropriate information.