Summarise the rules for writing of distribution of electrons in various shells for the first eighteen elements.
Science
Class 9
1166
Mukesh
The rules for writing of distribution of electrons in various shells for the first eighteen elements are:
The maximum number of electrons present in a shell is given by the formula is 2n2.
We take, the orbit number n i.e., n = 1, n = 2, and n = 3 for calculation. Now, Maximum number of electrons in different shells are:
The maximum number of electrons present in a shell is given by the formula is 2n2.
For K shell (n = 1) ⇒ 2n2 = 2(1)2 = 2, L shell (n = 2) ⇒ 2n2 = 2(2)2 = 8, M shell (n = 3) ⇒ 2n2 = 2(3)2 = 18, N shell (n = 4) ⇒ 2n2 = 2(4)2 = 32.
The distribution of electrons in different orbits or shells is governed by a scheme known as Bohr bury scheme.The arrangement of electrons in various energy levels of an atom is known as the electronic configuration of the atom. According to this scheme.
Maximum No. of electrons in different orbits
Orbit |
Value of n | Maximum no. of electrons in the orbit |
K |
1 | 2 × 12 = 2 |
L | 2 |
2 × 22 = 8 |
M |
3 | 2 × 32 = 18 |
N | 4 |
2 × 42 = 32 |
The outermost shell of an atom cannot have more than 8 electrons and the shell next to the outermost shell cannot have more than 18 electrons.