Question

According to the Bohr-Bury scheme, the maximum number of electrons which can be accommodated in a given shell is given by the formula:
A.$2{{\text{n}}^{2}}$
B.${{\text{n}}^{\text{2}}}$
C.$\text{3}{{\text{n}}^{2}}$
D.$2\text{n}$

Answer 1

Hint:The distribution of the electrons in the orbits or the shells of the atoms is governed by the Bohr-Bury Scheme. The arrangement of the electrons in various energy levels of an atom is called the electronic configuration of the atom.

Complete answer:
The rule of the Bohr-Bury Scheme can be stated as follows:
-The electrons in the atom are arranged around the nucleus in different shells and the electrons first occupy that shell which is closest to the nucleus as it has the lowest energy.
-The first or the innermost shell is called the K-shell which can take upto two electrons
-The second shell is called the L-shell which can take upto eight electrons.
-In the third shell, called the M-shell, total eighteen electrons can be accommodated.
-In general the total or the maximum number of electrons that can be accommodated in a shell is equal to $2{{\text{n}}^{2}}$, where n is the shell number or the principal quantum number.

Hence, the correct answer is option A.

Note:
For the K-shell, n = 1, putting the value of n in the above formula we get, the number of electrons that can accommodate the K-shell is $2{{\left( 1 \right)}^{2}}=2$. For the L-shell, n = 2, hence putting the value in the formula we get, $2{{\left( 2 \right)}^{2}}=8$, so the second shell can accommodate eight electrons and so on. The outermost shell of the atom cannot have more than eight electrons; the arrangement of the electrons in the shell is arranged in different orbitals.