The key difference between electropositive and electronegative is that electropositive refers to the ability to lose electrons, forming cations, whereas electronegative refers to the ability to gain electrons, forming anions.
The terms electropositive and electronegative come with the attraction or repulsion of chemical elements towards electrons. We can categorize chemical elements according to this characteristic; either they lose or gain electrons during a chemical reaction.
CONTENTS
1. Overview and Key Difference
2. What is Electropositive
3. What is Electronegative
4. Side by Side Comparison – Electropositive vs Electronegative in Tabular Form
5. Summary
What is Electropositive?
Electropositive means chemical elements tend to lose electrons. Losing electrons forms cations or positively charged ions in chemical reactions. It is a measure of an element’s ability to donate electrons. Elements tend to lose their electrons to gain a noble gas electron configuration.
Usually, all metals are considered as electropositive chemical elements because they have easily removable electrons in their outermost orbitals. Among them, the alkali metals (group 1 chemical elements) are the most electropositive elements. Theoretically, Francium is the most electropositive chemical element, though it is unstable in nature. Although hydrogen is in the group1 of the periodic table, it can either lose or gain electrons; therefore, we can categorize it under both electropositive and electronegative elements.
What is Electronegative?
Electronegative refers to the ability of a chemical element to gain electrons. The gaining of electrons from the outside forms anions; anions are the negatively charged chemical species. Electronegativity is the opposite of electropositivity. The symbol for this phenomena is χ. The term may refer to the attraction of either a shared pair of electrons or an electron density towards itself. There are two major factors that affect the electronegativity of a chemical element: atomic number and distance between nucleus and valence electrons.
Figure 01: Pauling Scale Values for Chemical Elements
The Pauling scale is the method we use to give a value to the electronegativity of a chemical element. The scale was proposed by Linus Pauling. It is a dimensionless quantity. Moreover, it is a relative scale which considers the electronegativity ranges from 0.79 to 3.98. The electronegativity of hydrogen is 2.20. The most electronegative element is fluorine, and its Pauling scale value is 3.98 (usually we take it as 4). Usually, all halogens (group 7 elements) are highly electronegative.
What is the Difference Between Electropositive and Electronegative?
The key difference between electropositive and electronegative is that the term electropositive refers to the ability to lose electrons, forming cations, whereas electronegative refers to the ability to gain electrons, forming anions. Furthermore, when considering the chemical elements in the top of the list, in electropositive elements list, the most electropositive element is Francium while among the electronegative elements, the most electronegative element is Fluorine.
The Pauling scale is the scale we use to give a value to each electropositive and electronegative element. However, this scale gives the electronegativity of an element; therefore, we can determine that a very low electronegativity value indicates that the element is more electropositive.
Below infographic summarizes the difference between electropositive and electronegative.
Summary – Electropositive vs Electronegative
The terms electropositive and electronegative describe the attraction or repulsion of chemical elements towards electrons. The key difference between electropositive and electronegative is that the term electropositive refers to the ability to lose electrons forming cations, whereas electronegative refers to the ability to gain electrons forming anions.
The Pauling scale is the scale we use to give a value to each electropositive and electronegative element. The scale gives the electronegativity of an element; therefore, we can determine that a very low electronegativity value indicates that the element is more electropositive.
Reference:
1.“Electronegativity.” Wikipedia, Wikimedia Foundation, 13 Sept. 2019, Available here.
2. “Why Metals Called Electropositive Elements ynosb3ss -Chemistry.” Topperlearning, Available here.
Image Courtesy:
1. “Electronegative” By Adblocker – Own work, (CC BY-SA 3.0) via Commons Wikimedia