Question

part a
name the compound li₃p.
○ trilithium phosphide
○ lithium phosphide
○ trilithium monophosphide
○ lithium(i) phosphide

Explanation:

To name the ionic compound \( \text{Li}_3\text{P} \), we first identify the ions. Lithium (\( \text{Li} \)) forms \( \text{Li}^+ \) (group 1 metal, charge is +1, no need for Roman numerals as it has a fixed charge). Phosphorus forms \( \text{P}^{3-} \) (phosphide ion). For ionic compounds with fixed - charge cations (like group 1 metals), we use the name of the cation (lithium) and the name of the anion (phosphide). We don't use prefixes (like "tri - ", "mono - ") because those are for covalent compounds, and we don't use Roman numerals here since lithium has a fixed oxidation state of +1. So the name should be lithium phosphide.

Answer:

B. lithium phosphide