Question

Name two ions with the same Lewis electron dot diagram as the Cl \(^{-}\) ion.

Short answer

The ions are oxide (O\(^{2-}\)) and sulfide (S\(^{2-}\)).

Step-by-step solution

Understanding the Problem

We need to find two ions that have the same Lewis electron dot diagram as the chloride ion, Cl\(^{-}\). Chloride ion has a full octet, similar to a noble gas configuration.

Identify the Chloride Ion Configuration

Chloride ion (Cl\(^{-}\)) achieves a noble gas configuration with 8 valence electrons, which is similar to the electron configuration of argon.

Find Elements Gaining Electrons

Elements that gain electrons to achieve a noble gas configuration similar to chloride are typically found just before the noble gases in the periodic table.

Locate Oxide Ion

The oxide ion (O\(^{2-}\)) gains 2 electrons to have a full octet, similar to neon's electron configuration, resembling the chloride ion's dot diagram.

Locate Sulfide Ion

The sulfide ion (S\(^{2-}\)) gains 2 electrons to have a full octet, mimicking the argon's electron configuration, same as the chloride ion's dot diagram.

Key concepts

Chloride Ion

The chloride ion, denoted as Cl\(^{-}\), forms when an atom of chlorine gains an extra electron. This process helps it achieve a stable electronic state. The resulting ion has a total of 8 valence electrons, represented as

• 7 electrons originally from chlorine
• 1 additional electron gained

This satisfies the octet rule, meaning the ion has a complete shell of electrons similar to a noble gas. When you draw a Lewis electron dot diagram for a chloride ion, you illustrate these 8 electrons surrounding the element symbol for chlorine (Cl) as dots.

Noble Gas Configuration

A noble gas configuration refers to the stable, complete electron arrangement seen in noble gases like neon and argon. These gases naturally have fully filled outer electron shells, making them particularly stable and unreactive. Other elements seek this stable structure by gaining or losing electrons.
When elements achieve a noble gas configuration, it means their electron arrangement mirrors that of a noble gas, which usually implies having 8 valence electrons (an octet). This is the case for ions like Cl\(^{-}\), O\(^{2-}\), and S\(^{2-}\). Such configurations contribute to the formation of stable ions in different chemical reactions.

Oxide Ion

The oxide ion, symbolized as O\(^{2-}\), forms when an oxygen atom gains two electrons. By acquiring these electrons, it achieves the electron configuration of neon, a noble gas.
The addition of two electrons to the oxygen atom fills its outer shell perfectly:

• 6 valence electrons from oxygen
• 2 electrons gained

In a Lewis electron dot diagram, you depict the oxide ion similar to the chloride ion using 8 dots around the "O" symbol, reflecting its stability and obedience to the octet rule.

Sulfide Ion

The sulfide ion, shown as S\(^{2-}\), results from a sulfur atom gaining two electrons. This gain allows sulfur to mirror the electron configuration of argon, another noble gas.
For the sulfide ion:

• There are 6 initial valence electrons from sulfur
• With 2 electrons gained, reaching 8 in total

Its Lewis electron dot diagram will display 8 dots around the sulfur symbol "S". Like the chloride and oxide ions, the sulfide ion follows the octet rule, signifying stability and reactivity reduction.