Question

The electron distribution in an aluminium atom is:
A) 2, 8, 3
B) 2, 8, 2
C) 8, 2, 3
D) 2, 3, 8

Answer 1

Hint: To write the electron configuration of Aluminium, we need to know the number of electrons present in the Al atom (there are 13 electrons). When we write the configuration we'll put all 13 electrons in orbitals around the nucleus of the Aluminium atom.

Complete step by step answer:
In an atom, the electrons revolve around the nucleus. The electrons are in separate shells/orbitals. The \[{1^{st}}\] shell can only hold 2 electrons, \[{2^{nd}}\]shell can hold 8, and for the first eighteen elements \[{3^{rd}}\] shell can hold a maximum of eight electrons. For elements with more than eighteen electrons \[{3^{rd}}\] shells can hold more than eight electrons. Once one shell is filled with an electron, the next electron jumps to the next shell.
So, Aluminium, we know that the atomic number tells about the number of electrons. We know that there are 13 electrons and 13 protons in an aluminium atom. Looking at the picture, we know that \[{1^{st}}\] shell can hold so there are two electrons in shell one, and \[{2^{nd}}\] shell can hold 8 electron so there are eight in shell two, and now only 3 electrons are left so they are distributed in the \[{3^{rd}}\] shell so three are 3 electron in shell three.
Therefore the Aluminium electron configuration will be \[1{s^2},2{s^2}2{p^6},3{s^2}3{p^1}\]
Thus,
K, L, M shell will have 2, 8, 3 electrons (as per \[2{n^2}\] rule). Therefore, the electronic configuration is 2, 8, and 3.
Therefore, option A is correct.

Note:
This configuration notation makes it easier for scientists to write and communicate how electrons are distributed around the nucleus of an atom. This makes it more understandable and tells about how atoms will interact to form chemical bonds.