Question

maximum no. of electrons that can be accommodated in a shell is given by 2n² , still why after a octet a new shell is formed?

Answer 1

According to octet rule ; the maximum number of electron that can accommodate in particular energy level is 8. But what next, if the number of electron is more than 8? It will go to next energy level or new shell.

For Ex.take element Sodium =Na, atomic no. 11, No. of electron 11, The filling of electron takes place like this; At first 2 electrons will occupy the 1st energy level remaining (11-2=9) will go to 2nd energy level.The 2nd level can accommodate 8 electrons only still 1 is left out(9-8=1) which will occupy the new energy level or shell.