Summarise the rules for writing of distribution of electrons in various shells for the first eighteen elements.
Following rules are to be followed to fill electrons in different energy levels.
i. If n gives the number of orbit or energy level, then 2n2 gives the maximum number of electrons possible in a given orbit or energy level. Thus K shell can have a maximum of 2 electrons, L shell can have a maximum of 8 electrons and M-shell can have a maximum of 18 electrons.
ii. If it is the outermost orbit, then it should not have more than 8 electrons.
iii. There should be stepwise filling of electrons in different orbits, i.e. electrons are not accomodated in a given orbit if the earlier orbits or shells are incompletely filled.