Which of the following can easily form an ionic bond with a cation?
Sr
Ne
[tex]$NH _4{ }^{+}$[/tex]
[tex]$PO _4{ }^{3-}$[/tex]
Answer (1)
Identify that ionic bonds form between oppositely charged ions.
Recognize that cations are positively charged.
Determine that P O 4 3 − is the only anion among the given options.
Conclude that P O 4 3 − can easily form an ionic bond with a cation: P O 4 3 −
Explanation
Understanding the Problem 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. Cations are positively charged ions. Therefore, we are looking for an anion (negatively charged ion) or a species that can easily become an anion.
Analyzing the Species Sr is an alkaline earth metal and readily forms a +2 cation ( S r 2 + ). Ne is a noble gas and is very stable, so it does not readily form ions. N H 4 + is a polyatomic cation with a +1 charge. P O 4 3 − is a polyatomic anion with a -3 charge. An ionic bond is easily formed between a cation and an anion.
Conclusion Therefore, the species that can easily form an ionic bond with a cation is P O 4 3 − , since it is an anion and will be attracted to cations due to opposite charges.
Examples
Ionic bonds are essential in many chemical compounds, such as table salt (NaCl). The positively charged sodium ion (Na+) forms an ionic bond with the negatively charged chloride ion (Cl-). This bond is formed due to the electrostatic attraction between the oppositely charged ions. Similarly, in the given problem, P O 4 3 − can form an ionic bond with a cation like N a + , K + , or C a 2 + to form various phosphate salts, which are crucial in biological systems and fertilizers.
