Explanation :
As we know that the electrons are located around the nucleus in an atom and the arrangement electrons depends upon of their potential energies in the different orbital or shell.
There are some rules of the distribution of electrons in the different shell.
Rule 1 : The maximum number of electrons present in a particular shell is calculated by the formula [tex]2n^2[/tex], where 'n' represents the shell number.
Rule 2 : The maximum capacity to hold the electrons in the outermost shell is 8.
Rule 3 : Once the first shell is full then the next electron is added to the next shell and so on. That means the shell number one i.e, 'K' can hold only two electrons, the shell number two i.e, 'L' can hold eight electrons, and so on.
The given atom is, helium with electronic configuration, [tex]1s^2[/tex]. The correct distribution of electrons in the electron shells of a helium atom are shown below.
