Question

How do valence electrons determine chemical properties?

Answer 1

Valence electrons are defined as the electrons that are present in the outermost shell of an atom. It helps us in determining the chemical properties of an element, the formation of bonds with other elements. It also helps us in determining how readily an atom can form bonds.

Complete step-by-step answer: Before talking about the answer, we should know about the valence electrons.
Let us discuss some characteristics of valence electrons-
A valence electron is present in the inner shell of a transition metal.
Valence electrons only exist in the outermost shell for main group elements.
A valence electron absorbs energy and also releases energy in a form of a photon.
It also helps in the determination of electrical conductivity of an element.
We can calculate valence electrons by examining the vertical columns known as groups. The group number tells us about the number of valence electrons present in an element. We can also determine valence electrons with the help of electronic configuration.
The group 1 elements have only one valence electron that means these electrons can easily be lost from a metal to form a positive ion. These metals are considered to be the most reactive elements.
Group 2 elements are less reactive than group 1 elements as it has two electrons that will easily be lost to form a positive ion.
Non metals have the tendency to attract electrons to form ionic or covalent bonds. Fluorine and chlorine are the most reactive nonmetals. They require one electron to complete its octet and acquire noble gas configuration.

Note: For the formation of a covalent bond, one electron from halogen and one electron from another atom form a shared pair. For example- $H-F$ and for the formation of ionic bond, a halogen atom can remove an electron from another atom so that it can form anion. For example- ${{F}^{-}}$