Write the distribution of electrons in carbon and sodium atoms.
Answer
Based on the BohrBury scheme, we know that the maximum number of electrons that can be present in a particular energy shell of an atom is given by 2n 2 , where “n” is the number of energy shells.
(i) Carbon
Atomic number of Carbon = 6
Therefore, number of electrons in Carbon = 6
 2 of them are held in K Shell (as K Shell can hold max 2 electrons)

4
of them are held in
L Shell
(as L Shell can hold max 8 electrons)
So,K Shell  2
L Shell  4
(ii) Sodium
Atomic number of Sodium = 11
Therefore, number of electrons in Sodium = 11
 2 of them are held in K Shell (as K Shell can hold max 2 electrons)
 8 of them are held in L Shell (as L Shell can hold max 8 electrons)
Remaining 1 is held in M Shell
So,
K Shell  2
L Shell  8
M Shell  1