Question

the chemical formula for lithium phosphide is li₃p. which best describes this ionic compound?
○ lithium ions have 1 positive charge, and phosphorus ions have 3 negative charges.
○ lithium ions have 3 positive charges, and phosphorus ions have 1 negative charge.
○ lithium ions have 1 negative charge, and phosphorus ions have 3 positive charges.
○ lithium ions have 3 negative charges, and phosphorus ions have 1 positive charge.

Explanation:

In an ionic compound, the overall charge is zero. Lithium (Li) is in group 1 of the periodic table and forms \(Li^+\) ions (charge \(+ 1\)). Phosphorus (P) is in group 15 and forms \(P^{3 -}\) ions. For the formula \(Li_3P\), if each Li has a \(+1\) charge (\(3\times(+1)=+3\)) and P has a \(-3\) charge (\(-3\)), then \(+3+( - 3)=0\).

Answer:

Lithium ions have 1 positive charge, and phosphorus ions have 3 negative charges.