Which things are not listed in the periodic table?

The correct answer to this question is the atomic Orbital radius. Also known as Bohr radius, the atomic orbital radius is a constant, which is physical. It is unit of length, and a0 and Bohr are its symbols. It is named after physicist Niels Bohr, who founded it in 1913.

Today, this radius is no longer used, but it is still essential in calculations that are done in atomic physics. The value of the radius is 5.291 772 109 03(80) x 10 -11 m. In SI units, the atomic Orbital radius is 5.29×10−11 m, and in natural groups, it is 2.68×10−4/eV; 3.27×1024 â„“P.