Which of the following can easily form an ionic bond with a cation?
A. Sr
B. Ne
C. [tex]$NH _4{ }^{+}$[/tex]
D. [tex]$PO _4{ }^{3-}$[/tex]
Answer (2)
Ionic bonds form between oppositely charged ions (cations and anions).
Sr forms a +2 cation, Ne is inert, N H 4 + is a +1 cation, and P O 4 3 − is a -3 anion.
Anions readily form ionic bonds with cations.
Therefore, P O 4 3 − can easily form an ionic bond with a cation: P O 4 3 − .
Explanation
Understanding Ionic Bonds We are given four chemical species: Sr, Ne, N H 4 + , and P O 4 3 − . We want to determine which of these can easily form an ionic bond with a cation. Ionic bonds are formed between ions of opposite charges (positive and negative). Cations are positively charged ions. Therefore, we are looking for an anion (negatively charged ion) among the given species.
Identifying Charges Let's analyze the charge of each species:
Sr (Strontium): Strontium is an alkaline earth metal. It tends to lose two electrons to form a +2 cation ( S r 2 + ).
Ne (Neon): Neon is a noble gas. Noble gases have a full valence shell and are chemically inert, meaning they don't readily form ions.
N H 4 + (Ammonium): Ammonium is a polyatomic ion with a +1 charge. It's a cation.
P O 4 3 − (Phosphate): Phosphate is a polyatomic ion with a -3 charge. It's an anion.
Determining the Anion Ionic bonds are formed between oppositely charged ions. A cation is positively charged, so it will readily form an ionic bond with an anion (a negatively charged ion). Among the given species, only P O 4 3 − is an anion. Therefore, P O 4 3 − can easily form an ionic bond with a cation.
Final Answer Therefore, the species that can easily form an ionic bond with a cation is P O 4 3 − .
Examples
Ionic bonds are essential in many chemical compounds, such as table salt (NaCl). Sodium (Na) readily loses an electron to form a cation ( N a + ), while chlorine (Cl) readily gains an electron to form an anion ( C l − ). The electrostatic attraction between these oppositely charged ions forms a strong ionic bond, resulting in the stable compound NaCl. Similarly, the phosphate ion ( P O 4 3 − ) can form ionic bonds with various cations, such as calcium ( C a 2 + ) in bone tissue, contributing to the structural integrity of biological systems.
The species that can easily form an ionic bond with a cation is P O 4 3 − (phosphate ion), as it is an anion. In contrast, Sr and N H 4 + are cations and Ne is inert. Ionic bonds require the interaction between oppositely charged ions, making P O 4 3 − the suitable choice.
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