Question

Explain the electronic configuration of atoms with an illustration.

Answer 1

Electronic configuration of atoms:

1. Electrons occupy different energy levels called orbits or shells.
2. The distribution of electrons in these orbits of an atom is governed by certain rules or conditions. These are known as Bohr and Bury Rules of electronic configuration.
3. Bohr and Bury simultaneously proposed the following rules for the distribution of electrons in different shells.

Rule 1: The maximum number of electrons that can be accommodated in a shell is equal to 2n² where ‘n’ is the quantum number of the shell (i.e., the serial number of the shell from the nucleus).
Shell Value of (n) Maximum number of electrons (2n2)

Shell	Value of (n)	Maximum number of electrons (2n2)
K	1	2 x 12 = 2
L	2	2 x 22 = 8
M	3	2 x 32 = 18
N	4	2 x 42 = 32

Rule 2: Shells are filled in a stepwise manner in the increasing order of energy.
Rule 3: The outermost shell of an atom cannot have more than 8 electrons even if it has the capacity to accommodate more electrons. For example Electronic configuration in Ca