Question

When oxygen and sulfur atoms become monatomic ions, how many electrons does each lose or gain? Which noble gas atom has the same number of electrons as an oxide ion? Which noble gas atom has the same number of electrons as a sulfide ion?

Short answer

Oxygen and sulfur gain 2 electrons each. Oxide ion matches neon; sulfide ion matches argon.

Step-by-step solution

Understanding Monatomic Ions

When atoms form monatomic ions, they either gain or lose electrons to achieve a stable electron configuration similar to that of the nearest noble gas. Oxygen and sulfur will gain electrons because they are nonmetals.

Determining Electrons Gained for Oxygen

Oxygen has 6 valence electrons. To achieve a full outer shell similar to neon, it needs a total of 8 electrons, thus it gains 2 electrons to form the oxide ion O^{2-}.

Determining Electrons Gained for Sulfur

Sulfur, like oxygen, has 6 valence electrons. To attain a stable electron configuration similar to argon, it also gains 2 electrons to form the sulfide ion S^{2-}.

Identifying the Noble Gas for Oxide Ion

The oxide ion O^{2-} has the same electron configuration as neon (Ne), with 10 electrons.

Identifying the Noble Gas for Sulfide Ion

The sulfide ion S^{2-} aligns with the electron configuration of argon (Ar), having 18 electrons.

Key concepts

Understanding Oxygen Ions

Oxygen atoms naturally possess six valence electrons. Valence electrons are the electrons found in the outermost shell of an atom. These are crucial, as they help determine how an atom can bond and react with other atoms. Oxygen atoms aspire to have their outer electron shell filled, which is a more stable configuration. By gaining two additional electrons, oxygen forms an oxide ion, denoted as \( O^{2-} \). Gaining electrons instead of losing them is typical behavior for nonmetals like oxygen, due to their position on the periodic table. This results in a negatively charged ion, as the number of electrons now exceeds the number of protons.

Exploring Sulfur Ions

Similar to oxygen, sulfur is a nonmetal with six valence electrons. To achieve a full outer shell of electrons, similar to its nearest noble gas, sulfur gains electrons. Sulfur atoms gain two electrons to become sulfide ions, represented by \( S^{2-} \). By adopting this electron gain strategy, sulfur reaches a more stable electron configuration. The additional electrons bring the total electron count in a sulfide ion to resemble that of the noble gas argon. This process of gaining electrons is key to many chemical reactions, especially those involving sulfur in compounds.

Achieving Noble Gas Electron Configuration

When atoms like oxygen and sulfur become ions, they tend to adopt an electron configuration akin to the nearest noble gas. Noble gases are chemically inert mainly due to their complete electron shells, which is a state many elements strive to achieve. For oxygen, when it gains two electrons to form \( O^{2-} \), it achieves the electron configuration - similar to neon, which is a stable configuration. For sulfur, gaining two electrons allows the formation of \( S^{2-} \). The electron count in \( S^{2-} \) is the same as that of argon, adding stability. This makes both their resulting ions more stable and less reactive.

Importance of Valence Electrons

Valence electrons play a crucial role in chemical reactions and bonding. The behavior of atoms during these reactions is primarily focused on achieving stability, often by trying to reach a noble gas configuration by either gaining, losing, or sharing valence electrons.Both oxygen and sulfur have six valence electrons. This is the reason why both elements are keen on gaining two electrons to fill up their outer shell. Understanding the number of valence electrons can predict how an element will behave chemically. This knowledge is crucial in determining the types of bonds they can form and how they interact with other elements, turning them into ions like \( O^{2-} \) and \( S^{2-} \). This deeply impacts basic chemical processes that define material properties and reactions.