Question

Put tick against correct choice and cross against the wrong choice
Which one of the following is a correct electronic configuration of sodium?
(A) 2,8
(B) 8,2,1
(C)2,1,8
(D) 2,8,1

Answer 1

Hint: Sodium is an alkali metal and is an s-block element. The octet rule states that atoms tend to form compounds in ways that give them eight valence electrons and thus the electron configuration of a noble gas.

Complete step by step solution: The electron configuration of an element describes how electrons are distributed in its atomic orbitals. Electron configurations of atoms follow a standard notation in which all electron-containing atomic subshells (with the number of electrons they hold written in superscript) are placed in a sequence.
Sodium is an alkali metal. The last electron of sodium is filled in the s-block, making it a s-block element. Sodium releases one electron from its outermost orbit to obtain stable electronic configuration, with 8 electrons in its valence orbital.
Atomic number of sodium is 11. Electronic configuration of sodium is 2, 8, 1.

Hence the correct option is the D option.

Note: The octet rule is a chemical rule of thumb that reflects the observation that main group elements tend to bond in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas. The octet rule is important in covalent bonding because sharing electrons gives both atoms a full valence shell. All atoms strive to achieve a full valence shell, just like the noble gases. This is the most stable electron arrangement.