Question

The wrong statement among the following is (1) The element with outer electronic configuration \(n s^{2} n p^{5}\) is more electronegative. (2) The units of electronegativity are eV. (3) The element with higher electronegativity value may act as an oxidising agent. (4) The atom of an electronegative element becomes an ion by gaining electrons.

Short answer

Statement (2) is incorrect since electronegativity is dimensionless and has no units.

Step-by-step solution

Understand Electronegativity

Electronegativity is the tendency of an atom to attract a bonding pair of electrons. It depends on the number of protons in the nucleus and the distance of the outer electrons from the nucleus.

Analyze Statement (1)

The element with the outer electronic configuration \(n s^{2} n p^{5}\) typically belongs to Group 17 (Halogens) which are highly electronegative. This statement is correct.

Analyze Statement (2)

Electronegativity is a dimensionless quantity and does not have units. This statement is incorrect as it suggests electronegativity has units of eV.

Analyze Statement (3)

Elements with higher electronegativity tend to attract electrons and can act as oxidizing agents by accepting electrons. This statement is correct.

Analyze Statement (4)

An atom of an electronegative element becomes an ion by gaining electrons, forming anions. This statement is correct.

Key concepts

Outer Electronic Configuration

Understanding the outer electronic configuration of an element is crucial in predicting its chemical behavior. The outer electronic configuration refers to the arrangement of electrons in the outermost shell of an atom. For example, an element with an outer electronic configuration of \(n s^{2} n p^{5}\) typically belongs to Group 17 of the periodic table, which includes elements like fluorine and chlorine. These elements are also known as halogens.

Halogens are highly reactive and have a strong tendency to gain one electron to achieve a full outer shell, resembling the stable configuration of the noble gases. This tendency to gain electrons makes them highly electronegative. They readily accept electrons when they react with other elements, making them powerful oxidizing agents.

Oxidizing Agents

An oxidizing agent is a substance that gains electrons in a chemical reaction and, in the process, is reduced. These agents facilitate the oxidation of another substance by accepting its electrons. Highly electronegative elements often act as oxidizing agents because of their strong tendency to attract and gain electrons.

For example:

• Oxygen (O₂) readily gains electrons to form oxide ions (O^2-).
• Halogens like chlorine (Cl₂) accept electrons to form chloride ions (Cl^-).

When these elements accept electrons from another substance, they cause that substance to lose electrons, or be oxidized. This ability to attract and gain electrons strongly is what makes higher electronegativity elements, such as those with an outer electronic configuration of \(n s^{2} n p^{5}\), effective oxidizing agents.

Electronegative Elements

Electronegativity is a measure of an atom's ability to attract and bind with electrons. It is a key concept in chemistry because it helps explain the bonding behavior of different elements. Highly electronegative elements, such as those found in the upper right corner of the periodic table (excluding noble gases), have a strong tendency to gain electrons to form negative ions.

Key points about electronegative elements:

• Electronegativity is a dimensionless quantity, meaning it does not have units.
• The Pauling scale is commonly used to quantify electronegativity, with values typically ranging from around 0.7 to 4.0.
• Fluorine is the most electronegative element, with a Pauling scale value of about 3.98.
• Electronegative elements are often found in groups 15, 16, and 17 of the periodic table.

One common misconception is that electronegativity has units such as eV (electron volts), but this is not true. It is important to remember that electronegativity is a relative scale and does not have physical units associated with it. Elements with high electronegativity values tend to form anions by gaining electrons, and they play a vital role in various chemical reactions, including acting as strong oxidizing agents.