Understanding Electropositivity and Electron Loss

Electropositivity is a chemical property that describes an atom's tendency to donate valence electrons and form positive ions (cations). Elements with high electropositivity readily give up electrons. This property is most characteristic of metals, especially alkali metals and alkaline earth metals, which are found on the left side of the periodic table.

Atoms strive to achieve a stable electron configuration, typically like that of the noble gases (which have a full valence electron shell). For some elements, especially metals, the easiest way to reach this stability is by losing valence electrons. For others, like nonmetals, it's easier to gain or share electrons.

Analyzing the Given Elements

Let's examine each of the provided options to determine which is a highly electropositive element that easily loses an electron:

• Cl (Chlorine): Chlorine is a nonmetal from Group 17 (Halogens). Atoms of chlorine have 7 valence electrons. To achieve a stable octet, chlorine atoms tend to gain one electron to form a chloride ion, Cl^-. Chlorine is highly electronegative, meaning it strongly attracts electrons, rather than readily giving them up.
• O (Oxygen): Oxygen is a nonmetal from Group 16 (Chalcogens). Oxygen atoms have 6 valence electrons. Oxygen typically gains two electrons to form an oxide ion, O^2-, or forms covalent bonds by sharing electrons. Oxygen is also highly electronegative.
• Na (Sodium): Sodium is an alkali metal from Group 1. Sodium atoms have just 1 valence electron. Removing this single valence electron results in a sodium ion, Na⁺, which has the stable electron configuration of Neon ($1s^2 2s^2 2p^6$). This process requires relatively little energy (low ionization energy), meaning sodium readily gives up its electron. Sodium is a highly electropositive element.
• N (Nitrogen): Nitrogen is a nonmetal from Group 15. Nitrogen atoms have 5 valence electrons. Nitrogen usually gains three electrons to form a nitride ion, N^3-, or forms covalent bonds. Nitrogen is moderately electronegative.

Identifying the Highly Electropositive Element

Comparing the tendencies of these elements, Sodium (Na) stands out as the one that most readily loses an electron to achieve a stable configuration. Alkali metals like Sodium are known for their high electropositivity and low ionization energies, making them highly reactive and prone to forming positive ions by losing their valence electron.

Therefore, Sodium is the element among the given options that is highly electropositive and readily gives up an electron to achieve a stable electronic configuration.

Conclusion

Based on the analysis of how each element achieves a stable electron configuration and its position in the periodic table (indicating its metallic or nonmetallic character), Sodium (Na) is clearly the highly electropositive element that readily loses an electron.

Revision Table: Electropositivity Key Concepts

• Electropositivity: Tendency of an atom to lose electrons and form positive ions.
• Electronegativity: Tendency of an atom to attract electrons.
• Metals: Generally electropositive (tend to lose electrons).
• Nonmetals: Generally electronegative (tend to gain or share electrons).
• Stable Configuration: Usually a full valence shell, like noble gases.

Additional Information: Trends in Electropositivity

Electropositivity generally decreases across a period from left to right in the periodic table as nuclear charge increases and atomic size decreases, making it harder to remove valence electrons. It generally increases down a group as atomic size increases and the valence electrons are further from the nucleus, reducing the attraction and making them easier to remove. Alkali metals (Group 1) are the most electropositive elements.