The distribution of electrons into different orbits of an atom, as suggested by Bohr, is 2 electrons in the K-orbit, 8 electrons in the L-orbit, and 18 electrons in the M-orbit. Niels Bohr and Bury suggested the distribution and arrangement of electrons in different shells. There are certain rules to be followed for the distribution of electrons among different shells. Bohr-Bury rules are as follows: (i) The maximum number of electrons present in a shell is given by the formula 2n2(where n is shell number). (ii) The maximum number of electrons that can be accommodated in the outermost orbit is 8. (iii) The electrons are not accommodated in a given shell unless the inner shells are filled.