Question

which of the following could form an ionic compound? check all that apply. na⁺ and f⁻ ca²⁺ and fe³⁺ cl⁻ and k⁺ o²⁻ and s²⁻

Explanation:

To determine which pairs can form an ionic compound, we check if one is a metal (or cation) and the other is a non - metal (or anion), as ionic compounds are formed between cations (positive ions) and anions (negative ions) through electrostatic attraction.

1. For $\boldsymbol{\ce{Na+}}$ and $\boldsymbol{\ce{F-}}$:

$\ce{Na+}$ is a cation (formed from the metal sodium) and $\ce{F-}$ is an anion (formed from the non - metal fluorine). The positive and negative charges will attract each other, and they can combine in a 1:1 ratio to form $\ce{NaF}$, an ionic compound.

2. For $\boldsymbol{\ce{Ca^{2+}}}$ and $\boldsymbol{\ce{Fe^{3+}}}$:

Both $\ce{Ca^{2+}}$ and $\ce{Fe^{3+}}$ are cations (positive ions). Since ionic compounds require the combination of positive and negative ions, two cations cannot form an ionic compound as there is no electrostatic attraction between two positive charges in the context of ionic bonding.

3. For $\boldsymbol{\ce{Cl-}}$ and $\boldsymbol{\ce{K+}}$:

$\ce{K+}$ is a cation (from the metal potassium) and $\ce{Cl-}$ is an anion (from the non - metal chlorine). They can combine in a 1:1 ratio to form $\ce{KCl}$, an ionic compound.

4. For $\boldsymbol{\ce{O^{2-}}}$ and $\boldsymbol{\ce{S^{2-}}}$:

Both $\ce{O^{2-}}$ and $\ce{S^{2-}}$ are anions (negative ions). Just like two cations, two anions cannot form an ionic compound as there is no electrostatic attraction between two negative charges for ionic bonding.

Answer:

A. $\ce{Na+}$ and $\ce{F-}$
C. $\ce{Cl-}$ and $\ce{K+}$