Find the Valency of an Element

To find the valency of an element, you need to determine the number of electrons an atom of that element gains, loses, or shares when it forms a chemical bond with other atoms. The valency is typically determined by examining the number of valence electrons—the electrons in the outermost energy level (shell) of the atom. Here's how you can find the valency of an element:

 

1. Identify the Element: Start by identifying the element for which you want to determine the valency. You can find the element's symbol on the periodic table.

2. Determine the Number of Valence Electrons: Find the group number (column number) of the element on the periodic table. For main group elements (groups 1, 2, and 13-18), the group number corresponds to the number of valence electrons. For example:

   • Group 1 elements (alkali metals) have 1 valence electron.
   • Group 2 elements (alkaline earth metals) have 2 valence electrons.
   • Group 13 elements (boron group) have 3 valence electrons.
   • Group 14 elements (carbon group) have 4 valence electrons.
   • Group 15 elements (nitrogen group) have 5 valence electrons.
   • Group 16 elements (oxygen group) have 6 valence electrons.
   • Group 17 elements (halogens) have 7 valence electrons.
   • Group 18 elements (noble gases) have a full outer shell and are chemically inert.

3. Determine the Valency: Once you know the number of valence electrons, you can determine the valency:

   • For elements in groups 1, 2, and 13, the valency is equal to the number of valence electrons.
   • For elements in groups 15-17, subtract the number of valence electrons from 8 to find the valency. For example, for nitrogen (group 15) with 5 valence electrons, the valency is 8 - 5 = 3.
   • For transition metals and inner transition metals, determining valency can be more complex due to multiple oxidation states. The valency may vary depending on the specific compound and the oxidation state of the metal ion.

4. Consider Compounds: The valency of an element may vary depending on the compound it forms. In covalent compounds, elements typically share electrons to achieve a stable electron configuration, while in ionic compounds, elements gain or lose electrons to achieve a full outer shell. The valency of an element in a compound is often indicated by its oxidation number.

 

By following these steps and considering the number of valence electrons, you can determine the valency of an element and understand its chemical behavior and reactivity.

 

 

Thank you,