Question

How to find valency of an element by the help of electronic confurigation confurigration?

Answer 1

See the no. of electrons in valence shell.

If the no. of electrons in valence shell us between 1 to 4 then you can directlysay that its that its valency will be +{no.of valence electrons}

But if the no.of valence electrons is between 5 to 8 {Assume it to be n which is between 5 to 8}

Then its valency will be -( 8- n )

Hope it helps you my dear friend..

Answer 2

$<b><i><u> HEYA DEAR....❤$
TOPIC :-
ELECTRONIC CONFIGURATION OF ELEMENTS -

The energy levels of electrons are denoted by the number 1, 2, 3, 4, 5 and 6 whereas shells are represented by the letters K, L, M, N, O and P .

1st energy level is K shell
2nd energy level is L shell, and so on.

✴The outermost shell of an atom is at the highest energy level.

✴ The valency of an element is decided by the number of electrons in its atom.

How to calculate Valency :-

Let me give you a few examples:-


Valency of Oxygen:

Oxygen is located in Group 6 and therefore has 6 valence electrons. It also has electron configuration of 2.6 and the last 6 shows the number of valence electrons. As 6 is lesser than 4, the valency of Magnesium is 8 - 6 = 2.

Valency of Magnesium:

Magnesium is located in Group 2 and therefore has 2 valence electrons. It also has electron configuration of 2.8.2 and the last 2 shows the number of valence electrons. As 2 is lesser than 4, the valency of Magnesium is 2.

Method :-

The valency of an element can be said in 2 ways depending on its outer-most electron shell.

First of all, the number of valence electrons (number of electrons in the outer-most shell) can be determined by either looking at the group (column number) in which the element is situated in the Periodic Table.

Now, after finding the number of valence electron, if the number is lesser than 4, the valency of the element is the same as the number of valence electrons. If the number of valence electrons are greater that 4, then you subtract the number of valence electrons from 8 (number of electrons in a complete outer shell) to calculate the valency of the element.

Hope it helps ✔