What is Electropositivity?
The measure of the ability of the elements, mainly metals, to donate electrons for the formation of the positive ions is called electropositivity. On the other hand, the elements which can easily accept the electrons for the formation of negative ions are known as electronegative elements. Non-metals are examples of electronegative elements.
It should be noted that electropositivity is opposite to electronegativity, which is a measure of atomic metals having the propensity to receive electrons and form poorly charged anions. And hence, light-emitting substances have very low electronegativities and very high-energy electrons have very low electropositivity. Electronegative elements usually have no metals and have the propensity to lose electrons to form cations, and electropositive metals substances usually do not receive electrons to form anions. The highest electropositive elements normally form ionic salts with electronegative elements. For instance, sodium is a highly electropositive metal that easily provides an electron to obtain a stable electron suspension. And Chlorine is a highly potent element that absorbs electrons to achieve a stable octet.
Define Electropositivity
Electropositivity can be defined as the tendency of an atom to donate electrons to form positively charged cations. The property to form positively charged cations is most probably exhibited by the metallic elements in the periodic table, especially the alkali metals and the alkaline earth metals.
Electropositivity is just the opposite of electronegativity. The highly electronegative elements have very low electropositivity whereas the highly electropositive elements have very low electronegativity. The electronegative elements usually form ionic salts with the electronegative elements. Sodium, which is a highly electropositive element, gives up an electron to obtain a stable electronic configuration. On the other hand, chlorine is a highly electronegative element that accepts an electron to achieve a stable octet.
Therefore, the electropositive element sodium and the electronegative element chlorine can form an ionic bond with each other to give sodium chloride. Sodium chloride is also known as common salt which is consumed every day.
Periodic Trends in The Electropositivity of The Elements
The electropositivity of an element depends on various factors like the metallic character of an element, the ionization energy of an element, the distance between the nucleus and the valence shell, and also the effective nuclear charge acting on the valence shell. The periodic trends in electropositivity exhibited by the elements are always opposite to the periodic trends in the electronegativities of the elements.
Electronegativity of the elements increases across a period whereas the electropositivity of the elements decreases across the periods, the electronegativity of the elements decreases down the group, and the electropositivity of the elements increases while traversing down a group. This is the reason why the elements at the top right of the periodic table are the least electropositive and the elements at the bottom left of the periodic table are always electropositive.
Electropositivity is a metallic attribute; it is dependent on the metallic character of an element. This is the only reason why all the alkali metals are regarded as the most electropositive elements in the periodic table. Caesium and francium are the highest electropositive elements in the entire periodic table. Whereas, fluorine, chlorine, and oxygen are the most electronegative elements in the periodic table which also means that they are the least electropositive elements in the periodic table.
Electropositivity is primarily a metallic property; hence it is influenced by the element’s metallic character. This is why alkali metals are considered to be the most electropositive elements e.g. with caesium and francium being the most electropositive elements in the entire periodic table.
Fluorine, oxygen, and chlorine are the least electropositive elements in the periodic table since they are the most electronegative.
Top 5 electropositive elements
The most selective feature in the timeline is Cesium (Cs). A list of the top five energy selection items is given below:
Caesium
Rubidium
Potassium
Sodium
Lithium
What is Electronegativity
The metals of an atom to a molecule to attract electrons distributed by itself is known as electronegativity. It is flawless material because it is just a habit. It shows the complete effect of the atomic inclination on various objects to attract pairs that form electrons. Measure electronegativity on several scales. The most widely used scale is designed by Linus Pauling. According to this scale, fluorine is a highly electronegative substance with a value of 4.0 and caesium is a small non-electrical substance with a value of 0.7.
Electropositive Character
The tendency of an element to lose the electrons to form the positive ions is called the electropositive character. It is also called the metal character. The elements which have very low ionization energies have a higher tendency to lose electrons and therefore they are electropositive or metallic in their behavior. The alkali metals are always the most highly electropositive elements.
Periodicity
The reactivity of the metal decreases from the left to the right in a period as the tendency of an element to lose electrons decreases.
The reactivity of the metals increases from the top to the bottom in a group because the tendency of an element to lose electrons increases in a period.
In a periodic table, the electropositivity or the metallic characters increases from the top to the bottom of the group.
Electropositive Elements
In a periodic table, the elements are usually divided into two groups. The first group of elements is called metals and the second group of the elements is known as the non-metals. The metals and the non-metals are also divided into two categories which include electropositive and electronegative.
The electropositive is those elements or groups that give up electrons i.e. metals and acidic hydrogen. Electropositive elements are those elements whose electrode potential is more positive than that of a standard hydrogen electrode which is assigned an arbitrary value of zero. Examples of univalent alkali metals are Li+, Na+, K+, etc. An example of divalent alkaline earth metals is Be2+, Mg2+, Ca2+.
What are Electropositive Radicals?
Electropositive radicals are atoms, ions, or molecules that can lose an electron and carry a positive electrical charge. An electropositive radical is formed due to the electropositive nature of a chemical species, which means a particular chemical species has the tendency to lose electrons in order to form positive radicals. Moreover, some examples of electropositive radicals include calcium cation (Ca+2), sodium cation (Na+), etc.
What are Electronegative Radicals?
Electronegative radicals are atoms, ions, or molecules that can gain an electron and carry a negative electrical charge. An electronegative radical is formed due to the high electronegativity of a chemical species, meaning, a particular chemical species have the tendency to gain electrons and form negatively charged radicals.
A radical, in chemistry, is an atom, molecule, or ion that contains an unpaired valence electron. The key difference between electropositive and electronegative radicals is that electropositive radicals are radical compounds having the capacity to lose electrons and carry a positive charge whereas electronegative radicals are radical compounds having the capacity to gain electrons and carry a negative charge. Most of the time, radicals are highly reactive chemical species which makes them undergo dimerization and polymerization reactions.
FAQs on Electropositivity
1. What is an electropositive element? Which is the most electropositive element in the periodic table? Also, name the least electropositive element in the modern periodic table.
Electropositive elements are those elements whose electrode potential is more positive than that of a standard hydrogen electrode which is assigned an arbitrary value of zero. Electropositive elements also tend to lose electrons and form positive ions. . Examples of univalent alkali metals are Li+, Na+, K+, etc. An example of divalent alkaline earth metals is Be2+, Mg2+, Ca2+.
In the periodic table, all the alkali metals among all the elements are considered to have the most electropositivity. Cesium is considered the most electropositive stable element. According to the theory, the most unstable electropositive element is believed to be Francium. The electropositivity of the elements is known to increase as one goes down the groups and starts decreasing across periods in the modern periodic table.
In the entire modern periodic table, Fluorine is considered to be the least electropositive element. Fluorine has the least tendency to donate an electron to form a cation.
2. What is the difference between electronegativity and electropositivity?
The electronegativity of an element is the tendency of an atom to attract in its combined state. It also shares a pair of bonded electrons. Whereas, the electropositivity of an element is the tendency of an atom to donate electrons and also withdraw from the covalent bonds only to form positively charged cations.
Non-metals are known as electronegative elements because they have high electronegativity in comparison with metallic elements. The metals are considered to be the most electropositive elements because they exhibit electropositivity. Fluorine is an example of an electronegative element and Caesium is an example of an electropositive element.
3. How to strengthen or lessen the electronegativity or electropositivity of a certain element?
Electronegativity is the measure of the tendency of an element to attract electrons and electropositivity is the tendency of an element to lose electrons. And I think it can be related to corrosion. Many ways are designed to stop corrosion and one way is through a sacrificial anode for cathodic protection. Sacrificial anodes, such as zinc, have more negative(less positive) electrode potential compared to iron, making it easier to be oxidized. (or easily lose electrons which makes it less electronegative and more electropositive). Now I want to know how to make an element, such as copper, more electropositive, to the point that it is more electropositive than iron and can be used as a sacrificial anode.
4. What is the difference between electropositive and electronegative?
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. 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.
