Question

how is the valency of an element determined from its position in the periodic table?

Answer 1

To find the elements of the periodic table, use the following steps:

To find the elements of the periodic table, use the following steps:

• Identify the atomic number of element from periodic table

• Find the electronic configuration

• You should identify the number of electrons in the last orbit

• If the number of electrons is less than or equal to 4, it denotes valency of the element

• In case the number of electrons is more than 4, valency =8-z where z is the number of valence electrons.

Answer 2

HEY!!

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▶▶The valency of an element refers to the number of elements in the outermost shell of the atom.

✴To Find the valency -:

✔Find out the atomic number ( position of the element in periodic table).

✔Find out the electronic configuration.

✔Check the number of electrons in the last orbit.

✔If the number of electron is ≤ 4 then the valency will be the number of electron present in outer shell.

✔If number of electron is > 4 then valency will be (8-n), where n is the number of electron present in outer most shell.

Example:- Valency of Nitrogen

▶Atomic number of nitrogen

7

▶Electronic configuration of Nitrogen

1S^2 2S^2  2p^3

▶Number of valence electrons

5

▶Number of electrons > 4, so valency is (8-5) 

3

✔✔So, valency of nitrogen is +3.